File: README.envvar

package info (click to toggle)
mpich 3.3-3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 131,836 kB
  • sloc: ansic: 975,868; cpp: 57,437; f90: 53,762; perl: 19,562; xml: 12,464; sh: 12,303; fortran: 7,875; makefile: 7,078; ruby: 126; java: 100; python: 98; lisp: 19; php: 8; sed: 4
file content (2343 lines) | stat: -rw-r--r-- 101,131 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
(C) 2010 by Argonne National Laboratory.
    See COPYRIGHT in top-level directory.

Automatically generated
  by:   ./maint/extractcvars
  at:   Wed Nov 21 11:33:20 2018
DO NOT EDIT!!!

This file lists the various environment variables available to change the
behavior of the MPICH library.  These are intended to be used by advanced
users.
---------------------------------------------------------------------------

MPIR_CVAR_PRINT_ERROR_STACK
    Aliases: MPIR_PARAM_PRINT_ERROR_STACK
             MPICH_PRINT_ERROR_STACK
    Description: If true, print an error stack trace at error handling
        time.
    Default: 1

MPIR_CVAR_CHOP_ERROR_STACK
    Aliases: MPIR_PARAM_CHOP_ERROR_STACK
             MPICH_CHOP_ERROR_STACK
    Description: If >0, truncate error stack output lines this many
        characters wide.  If 0, do not truncate, and if <0 use a sensible
        default.
    Default: 0

MPIR_CVAR_DIMS_VERBOSE
    Aliases: MPIR_PARAM_DIMS_VERBOSE
             MPICH_DIMS_VERBOSE
    Description: If true, enable verbose output about the actions of the
        implementation of MPI_Dims_create.
    Default: 0

MPIR_CVAR_EXSCAN_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_EXSCAN_INTRA_ALGORITHM
             MPICH_EXSCAN_INTRA_ALGORITHM
    Description: Variable to select allgather algorithm
        auto               - Internal algorithm selection
        nb                 - Force nonblocking algorithm
        recursive_doubling - Force recursive doubling algorithm
    Default: "auto"

MPIR_CVAR_EXSCAN_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_EXSCAN_DEVICE_COLLECTIVE
             MPICH_EXSCAN_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Exscan will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level exscan function will not be called.
    Default: 1

MPIR_CVAR_IREDUCE_SCATTER_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_RECEXCH_KVAL
             MPICH_IREDUCE_SCATTER_RECEXCH_KVAL
    Description: k value for recursive exchange based ireduce_scatter
    Default: 2

MPIR_CVAR_IREDUCE_SCATTER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_INTRA_ALGORITHM
             MPICH_IREDUCE_SCATTER_INTRA_ALGORITHM
    Description: Variable to select ireduce_scatter algorithm
        auto               - Internal algorithm selection
        noncommutative     - Force noncommutative algorithm
        recursive_doubling - Force recursive doubling algorithm
        pairwise           - Force pairwise algorithm
        recursive_halving  - Force recursive halving algorithm
        recexch  - Force generic transport recursive exchange algorithm
    Default: "auto"

MPIR_CVAR_IREDUCE_SCATTER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_INTER_ALGORITHM
             MPICH_IREDUCE_SCATTER_INTER_ALGORITHM
    Description: Variable to select ireduce_scatter algorithm
        auto                         - Internal algorithm selection
        remote_reduce_local_scatterv - Force remote-reduce-local-scatterv
        algorithm
    Default: "auto"

MPIR_CVAR_IREDUCE_SCATTER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_DEVICE_COLLECTIVE
             MPICH_IREDUCE_SCATTER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ireduce_scatter will allow the device
        to override the MPIR-level collective algorithms. The device still
        has the option to call the MPIR-level algorithms manually. If set
        to false, the device-level ireduce_scatter function will not be
        called.
    Default: 1

MPIR_CVAR_IALLTOALLW_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IALLTOALLW_INTRA_ALGORITHM
             MPICH_IALLTOALLW_INTRA_ALGORITHM
    Description: Variable to select ialltoallw algorithm
        auto              - Internal algorithm selection
        blocked           - Force blocked algorithm
        inplace           - Force inplace algorithm
        pairwise_exchange - Force pairwise exchange algorithm
    Default: "auto"

MPIR_CVAR_IALLTOALLW_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IALLTOALLW_INTER_ALGORITHM
             MPICH_IALLTOALLW_INTER_ALGORITHM
    Description: Variable to select ialltoallw algorithm
        auto - Internal algorithm selection
    Default: "auto"

MPIR_CVAR_IALLTOALLW_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IALLTOALLW_DEVICE_COLLECTIVE
             MPICH_IALLTOALLW_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ialltoallw will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level ialltoallw function will not be called.
    Default: 1

MPIR_CVAR_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
             MPICH_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
    Description: Variable to select neighbor_alltoallw algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM
             MPICH_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM
    Description: Variable to select neighbor_alltoallw algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
             MPICH_NEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
    Description: If set to true, MPI_neighbor_alltoallw will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level neighbor_alltoallw function will not
        be called.
    Default: 1

MPIR_CVAR_IALLTOALLV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IALLTOALLV_INTRA_ALGORITHM
             MPICH_IALLTOALLV_INTRA_ALGORITHM
    Description: Variable to select ialltoallv algorithm
        auto              - Internal algorithm selection
        blocked           - Force blocked algorithm
        inplace           - Force inplace algorithm
        pairwise_exchange - Force pairwise exchange algorithm
    Default: "auto"

MPIR_CVAR_IALLTOALLV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IALLTOALLV_INTER_ALGORITHM
             MPICH_IALLTOALLV_INTER_ALGORITHM
    Description: Variable to select ialltoallv algorithm
        auto - Internal algorithm selection
    Default: "auto"

MPIR_CVAR_IALLTOALLV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IALLTOALLV_DEVICE_COLLECTIVE
             MPICH_IALLTOALLV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ialltoallv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level ialltoallv function will not be called.
    Default: 1

MPIR_CVAR_ALLGATHERV_PIPELINE_MSG_SIZE
    Aliases: MPIR_PARAM_ALLGATHERV_PIPELINE_MSG_SIZE
             MPICH_ALLGATHERV_PIPELINE_MSG_SIZE
    Description: The smallest message size that will be used for the
        pipelined, large-message, ring algorithm in the MPI_Allgatherv
        implementation.
    Default: 32768

MPIR_CVAR_ALLGATHERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ALLGATHERV_INTRA_ALGORITHM
             MPICH_ALLGATHERV_INTRA_ALGORITHM
    Description: Variable to select allgatherv algorithm
        auto               - Internal algorithm selection
        brucks             - Force brucks algorithm
        nb                 - Force nonblocking algorithm
        recursive_doubling - Force recursive doubling algorithm
        ring               - Force ring algorithm
    Default: "auto"

MPIR_CVAR_ALLGATHERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ALLGATHERV_INTER_ALGORITHM
             MPICH_ALLGATHERV_INTER_ALGORITHM
    Description: Variable to select allgatherv algorithm
        auto                      - Internal algorithm selection
        nb                        - Force nonblocking algorithm
        remote_gather_local_bcast - Force remote-gather-local-bcast
        algorithm
    Default: "auto"

MPIR_CVAR_ALLGATHERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ALLGATHERV_DEVICE_COLLECTIVE
             MPICH_ALLGATHERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Allgatherv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level allgatherv function will not be called.
    Default: 1

MPIR_CVAR_ALLREDUCE_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_ALLREDUCE_SHORT_MSG_SIZE
             MPICH_ALLREDUCE_SHORT_MSG_SIZE
    Description: the short message algorithm will be used if the send
        buffer size is <= this value (in bytes)
    Default: 2048

MPIR_CVAR_ENABLE_SMP_COLLECTIVES
    Aliases: MPIR_PARAM_ENABLE_SMP_COLLECTIVES
             MPICH_ENABLE_SMP_COLLECTIVES
    Description: Enable SMP aware collective communication.
    Default: 1

MPIR_CVAR_ENABLE_SMP_ALLREDUCE
    Aliases: MPIR_PARAM_ENABLE_SMP_ALLREDUCE
             MPICH_ENABLE_SMP_ALLREDUCE
    Description: Enable SMP aware allreduce.
    Default: 1

MPIR_CVAR_MAX_SMP_ALLREDUCE_MSG_SIZE
    Aliases: MPIR_PARAM_MAX_SMP_ALLREDUCE_MSG_SIZE
             MPICH_MAX_SMP_ALLREDUCE_MSG_SIZE
    Description: Maximum message size for which SMP-aware allreduce is
        used.  A value of '0' uses SMP-aware allreduce for all message
        sizes.
    Default: 0

MPIR_CVAR_ALLREDUCE_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ALLREDUCE_INTRA_ALGORITHM
             MPICH_ALLREDUCE_INTRA_ALGORITHM
    Description: Variable to select allreduce algorithm
        auto                     - Internal algorithm selection
        nb                       - Force nonblocking algorithm
        recursive_doubling       - Force recursive doubling algorithm
        reduce_scatter_allgather - Force reduce scatter allgather algorithm
    Default: "auto"

MPIR_CVAR_ALLREDUCE_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ALLREDUCE_INTER_ALGORITHM
             MPICH_ALLREDUCE_INTER_ALGORITHM
    Description: Variable to select allreduce algorithm
        auto                  - Internal algorithm selection
        nb                    - Force nonblocking algorithm
        reduce_exchange_bcast - Force reduce-exchange-bcast algorithm
    Default: "auto"

MPIR_CVAR_ALLREDUCE_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ALLREDUCE_DEVICE_COLLECTIVE
             MPICH_ALLREDUCE_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Allreduce will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level allreduce function will not be called.
    Default: 1

MPIR_CVAR_IGATHER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IGATHER_INTRA_ALGORITHM
             MPICH_IGATHER_INTRA_ALGORITHM
    Description: Variable to select igather algorithm
        auto     - Internal algorithm selection
        binomial - Force binomial algorithm
        tree     - Force genetric transport based tree algorithm
    Default: "auto"

MPIR_CVAR_IGATHER_TREE_KVAL
    Aliases: MPIR_PARAM_IGATHER_TREE_KVAL
             MPICH_IGATHER_TREE_KVAL
    Description: k value for tree based igather
    Default: 2

MPIR_CVAR_IGATHER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IGATHER_INTER_ALGORITHM
             MPICH_IGATHER_INTER_ALGORITHM
    Description: Variable to select igather algorithm
        auto        - Internal algorithm selection
        long_inter  - Force long inter algorithm
        short_inter - Force short inter algorithm
    Default: "auto"

MPIR_CVAR_IGATHER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IGATHER_DEVICE_COLLECTIVE
             MPICH_IGATHER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Igather will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level igather function will not be called.
    Default: 1

MPIR_CVAR_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM
             MPICH_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM
    Description: Variable to select neighbor_alltoall algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLTOALL_INTER_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_INTER_ALGORITHM
             MPICH_NEIGHBOR_ALLTOALL_INTER_ALGORITHM
    Description: Variable to select neighbor_alltoall algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
             MPICH_NEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
    Description: If set to true, MPI_neighbor_alltoall will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level neighbor_alltoall function will not
        be called.
    Default: 1

MPIR_CVAR_IALLTOALL_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IALLTOALL_INTRA_ALGORITHM
             MPICH_IALLTOALL_INTRA_ALGORITHM
    Description: Variable to select ialltoall algorithm
        auto              - Internal algorithm selection
        brucks            - Force brucks algorithm
        inplace           - Force inplace algorithm
        pairwise          - Force pairwise algorithm
        permuted_sendrecv - Force permuted sendrecv algorithm
    Default: "auto"

MPIR_CVAR_IALLTOALL_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IALLTOALL_INTER_ALGORITHM
             MPICH_IALLTOALL_INTER_ALGORITHM
    Description: Variable to select ialltoall algorithm
        auto              - Internal algorithm selection
        pairwise_exchange - Force pairwise exchange algorithm
    Default: "auto"

MPIR_CVAR_IALLTOALL_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IALLTOALL_DEVICE_COLLECTIVE
             MPICH_IALLTOALL_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ialltoall will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level ialltoall function will not be called.
    Default: 1

MPIR_CVAR_SCATTER_INTER_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_SCATTER_INTER_SHORT_MSG_SIZE
             MPICH_SCATTER_INTER_SHORT_MSG_SIZE
    Description: use the short message algorithm for intercommunicator
        MPI_Scatter if the send buffer size is < this value (in bytes)
    Default: 2048

MPIR_CVAR_SCATTER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_SCATTER_INTRA_ALGORITHM
             MPICH_SCATTER_INTRA_ALGORITHM
    Description: Variable to select scatter algorithm
        auto     - Internal algorithm selection
        binomial - Force binomial algorithm
        nb       - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_SCATTER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_SCATTER_INTER_ALGORITHM
             MPICH_SCATTER_INTER_ALGORITHM
    Description: Variable to select scatter algorithm
        auto                      - Internal algorithm selection
        linear                    - Force linear algorithm
        nb                        - Force nonblocking algorithm
        remote_send_local_scatter - Force remote-send-local-scatter
        algorithm
    Default: "auto"

MPIR_CVAR_SCATTER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_SCATTER_DEVICE_COLLECTIVE
             MPICH_SCATTER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Scatter will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level scatter function will not be called.
    Default: 1

MPIR_CVAR_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
             MPICH_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
    Description: Variable to select neighbor_allgatherv algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM
             MPICH_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM
    Description: Variable to select neighbor_allgatherv algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
             MPICH_NEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_neighbor_allgatherv will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level neighbor_allgatherv function will
        not be called.
    Default: 1

MPIR_CVAR_IREDUCE_TREE_KVAL
    Aliases: MPIR_PARAM_IREDUCE_TREE_KVAL
             MPICH_IREDUCE_TREE_KVAL
    Description: k value for tree (kary, knomial, etc.) based ireduce
    Default: 2

MPIR_CVAR_IREDUCE_TREE_TYPE
    Aliases: MPIR_PARAM_IREDUCE_TREE_TYPE
             MPICH_IREDUCE_TREE_TYPE
    Description: Tree type for tree based ireduce kary      - kary tree
        knomial_1 - knomial_1 tree knomial_2 - knomial_2 tree
    Default: "kary"

MPIR_CVAR_IREDUCE_TREE_PIPELINE_CHUNK_SIZE
    Aliases: MPIR_PARAM_IREDUCE_TREE_PIPELINE_CHUNK_SIZE
             MPICH_IREDUCE_TREE_PIPELINE_CHUNK_SIZE
    Description: Maximum chunk size (in bytes) for pipelining in tree based
        ireduce. Default value is 0, that is, no pipelining by default
    Default: -1

MPIR_CVAR_IREDUCE_RING_CHUNK_SIZE
    Aliases: MPIR_PARAM_IREDUCE_RING_CHUNK_SIZE
             MPICH_IREDUCE_RING_CHUNK_SIZE
    Description: Maximum chunk size (in bytes) for pipelining in ireduce
        ring algorithm. Default value is 0, that is, no pipelining by
        default
    Default: 0

MPIR_CVAR_IREDUCE_TREE_BUFFER_PER_CHILD
    Aliases: MPIR_PARAM_IREDUCE_TREE_BUFFER_PER_CHILD
             MPICH_IREDUCE_TREE_BUFFER_PER_CHILD
    Description: If set to true, a rank in tree algorithms will allocate a
        dedicated buffer for every child it receives data from. This would
        mean more memory consumption but it would allow preposting of the
        receives and hence reduce the number of unexpected messages. If set
        to false, there is only one buffer that is used to receive the data
        from all the children. The receives are therefore serialized, that
        is, only one receive can be posted at a time.
    Default: 0

MPIR_CVAR_IREDUCE_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IREDUCE_INTRA_ALGORITHM
             MPICH_IREDUCE_INTRA_ALGORITHM
    Description: Variable to select ireduce algorithm
        auto                  - Internal algorithm selection
        binomial              - Force binomial algorithm
        reduce_scatter_gather - Force reduce scatter gather algorithm
        tree                  - Force Generic Transport Tree
        ring                  - Force Generic Transport Ring
    Default: "auto"

MPIR_CVAR_IREDUCE_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IREDUCE_INTER_ALGORITHM
             MPICH_IREDUCE_INTER_ALGORITHM
    Description: Variable to select ireduce algorithm
        auto                     - Internal algorithm selection
        local_reduce_remote_send - Force local-reduce-remote-send algorithm
    Default: "auto"

MPIR_CVAR_IREDUCE_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IREDUCE_DEVICE_COLLECTIVE
             MPICH_IREDUCE_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ireduce will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level ireduce function will not be called.
    Default: 1

MPIR_CVAR_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
             MPICH_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
    Description: Variable to select reduce_scatter_block algorithm
        auto               - Internal algorithm selection
        noncommutative     - Force noncommutative algorithm
        recursive_doubling - Force recursive doubling algorithm
        pairwise           - Force pairwise algorithm
        recursive_halving  - Force recursive halving algorithm
        nb                 - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM
    Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM
             MPICH_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM
    Description: Variable to select reduce_scatter_block algorithm
        auto                        - Internal algorithm selection
        nb                          - Force nonblocking algorithm
        remote_reduce_local_scatter - Force remote-reduce-local-scatter
        algorithm
    Default: "auto"

MPIR_CVAR_REDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
             MPICH_REDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Reduce_scatter_block will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level reduce_scatter_block function will
        not be called.
    Default: 1

MPIR_CVAR_GATHERV_INTER_SSEND_MIN_PROCS
    Aliases: MPIR_PARAM_GATHERV_INTER_SSEND_MIN_PROCS
             MPICH_GATHERV_INTER_SSEND_MIN_PROCS
    Description: Use Ssend (synchronous send) for intercommunicator
        MPI_Gatherv if the "group B" size is >= this value.  Specifying
        "-1" always avoids using Ssend.  For backwards compatibility,
        specifying "0" uses the default value.
    Default: 32

MPIR_CVAR_GATHERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_GATHERV_INTRA_ALGORITHM
             MPICH_GATHERV_INTRA_ALGORITHM
    Description: Variable to select gatherv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
        nb     - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_GATHERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_GATHERV_INTER_ALGORITHM
             MPICH_GATHERV_INTER_ALGORITHM
    Description: Variable to select gatherv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
        nb     - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_GATHERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_GATHERV_DEVICE_COLLECTIVE
             MPICH_GATHERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Gatherv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level gatherv function will not be called.
    Default: 1

MPIR_CVAR_ISCATTER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ISCATTER_INTRA_ALGORITHM
             MPICH_ISCATTER_INTRA_ALGORITHM
    Description: Variable to select iscatter algorithm
        auto     - Internal algorithm selection
        binomial - Force binomial algorithm
        tree     - Force genetric transport based tree algorithm
    Default: "auto"

MPIR_CVAR_ISCATTER_TREE_KVAL
    Aliases: MPIR_PARAM_ISCATTER_TREE_KVAL
             MPICH_ISCATTER_TREE_KVAL
    Description: k value for tree based iscatter
    Default: 2

MPIR_CVAR_ISCATTER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ISCATTER_INTER_ALGORITHM
             MPICH_ISCATTER_INTER_ALGORITHM
    Description: Variable to select iscatter algorithm
        auto                      - Internal algorithm selection
        linear                    - Force linear algorithm
        remote_send_local_scatter - Force remote-send-local-scatter
        algorithm
    Default: "auto"

MPIR_CVAR_ISCATTER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ISCATTER_DEVICE_COLLECTIVE
             MPICH_ISCATTER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iscatter will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iscatter function will not be called.
    Default: 1

MPIR_CVAR_PROGRESS_MAX_COLLS
    Aliases: MPIR_PARAM_PROGRESS_MAX_COLLS
             MPICH_PROGRESS_MAX_COLLS
    Description: Maximum number of collective operations at a time that the
        progress engine should make progress on
    Default: 8

MPIR_CVAR_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM
             MPICH_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM
    Description: Variable to select ineighbor_allgather algorithm
        auto - Internal algorithm selection
        nb   - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLGATHER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_INTER_ALGORITHM
             MPICH_NEIGHBOR_ALLGATHER_INTER_ALGORITHM
    Description: Variable to select ineighbor_allgather algorithm
        auto - Internal algorithm selection
        nb   - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
             MPICH_NEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_neighbor_allgather will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level neighbor_allgather function will not
        be called.
    Default: 1

MPIR_CVAR_ALLGATHER_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_ALLGATHER_SHORT_MSG_SIZE
             MPICH_ALLGATHER_SHORT_MSG_SIZE
    Description: For MPI_Allgather and MPI_Allgatherv, the short message
        algorithm will be used if the send buffer size is < this value (in
        bytes). (See also: MPIR_CVAR_ALLGATHER_LONG_MSG_SIZE)
    Default: 81920

MPIR_CVAR_ALLGATHER_LONG_MSG_SIZE
    Aliases: MPIR_PARAM_ALLGATHER_LONG_MSG_SIZE
             MPICH_ALLGATHER_LONG_MSG_SIZE
    Description: For MPI_Allgather and MPI_Allgatherv, the long message
        algorithm will be used if the send buffer size is >= this value (in
        bytes) (See also: MPIR_CVAR_ALLGATHER_SHORT_MSG_SIZE)
    Default: 524288

MPIR_CVAR_ALLGATHER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ALLGATHER_INTRA_ALGORITHM
             MPICH_ALLGATHER_INTRA_ALGORITHM
    Description: Variable to select allgather algorithm
        auto               - Internal algorithm selection
        brucks             - Force brucks algorithm
        nb                 - Force nonblocking algorithm
        recursive_doubling - Force recursive doubling algorithm
        ring               - Force ring algorithm
    Default: "auto"

MPIR_CVAR_ALLGATHER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ALLGATHER_INTER_ALGORITHM
             MPICH_ALLGATHER_INTER_ALGORITHM
    Description: Variable to select allgather algorithm
        auto                      - Internal algorithm selection
        local_gather_remote_bcast - Force local-gather-remote-bcast
        algorithm
        nb                        - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_ALLGATHER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ALLGATHER_DEVICE_COLLECTIVE
             MPICH_ALLGATHER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Allgather will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level allgather function will not be called.
    Default: 1

MPIR_CVAR_ALLTOALLV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ALLTOALLV_INTRA_ALGORITHM
             MPICH_ALLTOALLV_INTRA_ALGORITHM
    Description: Variable to select alltoallv algorithm
        auto                      - Internal algorithm selection
        nb                        - Force nonblocking algorithm
        pairwise_sendrecv_replace - Force pairwise_sendrecv_replace
        algorithm
        scattered                 - Force scattered algorithm
    Default: "auto"

MPIR_CVAR_ALLTOALLV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ALLTOALLV_INTER_ALGORITHM
             MPICH_ALLTOALLV_INTER_ALGORITHM
    Description: Variable to select alltoallv algorithm
        auto              - Internal algorithm selection
        pairwise_exchange - Force pairwise exchange algorithm
        nb                - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_ALLTOALLV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ALLTOALLV_DEVICE_COLLECTIVE
             MPICH_ALLTOALLV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Alltoallv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level alltoallv function will not be called.
    Default: 1

MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_ALLTOALL_SHORT_MSG_SIZE
             MPICH_ALLTOALL_SHORT_MSG_SIZE
    Description: the short message algorithm will be used if the
        per-destination message size (sendcount*size(sendtype)) is <= this
        value (See also: MPIR_CVAR_ALLTOALL_MEDIUM_MSG_SIZE)
    Default: 256

MPIR_CVAR_ALLTOALL_MEDIUM_MSG_SIZE
    Aliases: MPIR_PARAM_ALLTOALL_MEDIUM_MSG_SIZE
             MPICH_ALLTOALL_MEDIUM_MSG_SIZE
    Description: the medium message algorithm will be used if the
        per-destination message size (sendcount*size(sendtype)) is <= this
        value and larger than MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE (See also:
        MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE)
    Default: 32768

MPIR_CVAR_ALLTOALL_THROTTLE
    Aliases: MPIR_PARAM_ALLTOALL_THROTTLE
             MPICH_ALLTOALL_THROTTLE
    Description: max no. of irecvs/isends posted at a time in some alltoall
        algorithms. Setting it to 0 causes all irecvs/isends to be posted
        at once
    Default: 32

MPIR_CVAR_ALLTOALL_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ALLTOALL_INTRA_ALGORITHM
             MPICH_ALLTOALL_INTRA_ALGORITHM
    Description: Variable to select alltoall algorithm
        auto                      - Internal algorithm selection
        brucks                    - Force brucks algorithm
        nb                        - Force nonblocking algorithm
        pairwise                  - Force pairwise algorithm
        pairwise_sendrecv_replace - Force pairwise sendrecv replace
        algorithm
        scattered                 - Force scattered algorithm
    Default: "auto"

MPIR_CVAR_ALLTOALL_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ALLTOALL_INTER_ALGORITHM
             MPICH_ALLTOALL_INTER_ALGORITHM
    Description: Variable to select alltoall algorithm
        auto              - Internal algorithm selection
        nb                - Force nonblocking algorithm
        pairwise_exchange - Force pairwise exchange algorithm
    Default: "auto"

MPIR_CVAR_ALLTOALL_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ALLTOALL_DEVICE_COLLECTIVE
             MPICH_ALLTOALL_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Alltoall will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level alltoall function will not be called.
    Default: 1

MPIR_CVAR_IALLREDUCE_TREE_KVAL
    Aliases: MPIR_PARAM_IALLREDUCE_TREE_KVAL
             MPICH_IALLREDUCE_TREE_KVAL
    Description: k value for tree based iallreduce (for tree_kary and
        tree_knomial)
    Default: 2

MPIR_CVAR_IALLREDUCE_TREE_PIPELINE_CHUNK_SIZE
    Aliases: MPIR_PARAM_IALLREDUCE_TREE_PIPELINE_CHUNK_SIZE
             MPICH_IALLREDUCE_TREE_PIPELINE_CHUNK_SIZE
    Description: Maximum chunk size (in bytes) for pipelining in tree based
        iallreduce (tree_kary and tree_knomial). Default value is 0, that
        is, no pipelining by default
    Default: -1

MPIR_CVAR_IALLREDUCE_TREE_BUFFER_PER_CHILD
    Aliases: MPIR_PARAM_IALLREDUCE_TREE_BUFFER_PER_CHILD
             MPICH_IALLREDUCE_TREE_BUFFER_PER_CHILD
    Description: If set to true, a rank in tree_kary and tree_knomial
        algorithms will allocate a dedicated buffer for every child it
        receives data from. This would mean more memory consumption but it
        would allow preposting of the receives and hence reduce the number
        of unexpected messages. If set to false, there is only one buffer
        that is used to receive the data from all the children. The
        receives are therefore serialized, that is, only one receive can be
        posted at a time.
    Default: 0

MPIR_CVAR_IALLREDUCE_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IALLREDUCE_RECEXCH_KVAL
             MPICH_IALLREDUCE_RECEXCH_KVAL
    Description: k value for recursive exchange based iallreduce
    Default: 2

MPIR_CVAR_IALLREDUCE_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IALLREDUCE_INTRA_ALGORITHM
             MPICH_IALLREDUCE_INTRA_ALGORITHM
    Description: Variable to select iallreduce algorithm
        auto                     - Internal algorithm selection
        naive                    - Force naive algorithm
        recursive_doubling       - Force recursive doubling algorithm
        reduce_scatter_allgather - Force reduce scatter allgather algorithm
        recexch_single_buffer    - Force generic transport recursive
        exchange with single buffer for receives
        recexch_multiple_buffer  - Force generic transport recursive
        exchange with multiple buffers for receives
    Default: "auto"

MPIR_CVAR_IALLREDUCE_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IALLREDUCE_INTER_ALGORITHM
             MPICH_IALLREDUCE_INTER_ALGORITHM
    Description: Variable to select iallreduce algorithm
        auto                      - Internal algorithm selection
        remote_reduce_local_bcast - Force remote-reduce-local-bcast
        algorithm
    Default: "auto"

MPIR_CVAR_IALLREDUCE_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IALLREDUCE_DEVICE_COLLECTIVE
             MPICH_IALLREDUCE_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iallreduce will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iallreduce function will not be called.
    Default: 1

MPIR_CVAR_IEXSCAN_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IEXSCAN_INTRA_ALGORITHM
             MPICH_IEXSCAN_INTRA_ALGORITHM
    Description: Variable to select iexscan algorithm
        auto               - Internal algorithm selection
        recursive_doubling - Force recursive doubling algorithm
    Default: "auto"

MPIR_CVAR_IEXSCAN_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IEXSCAN_DEVICE_COLLECTIVE
             MPICH_IEXSCAN_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iexscan will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iexscan function will not be called.
    Default: 1

MPIR_CVAR_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
             MPICH_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
    Description: Variable to select ineighbor_alltoallw algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM
             MPICH_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM
    Description: Variable to select ineighbor_alltoallw algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
             MPICH_INEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
    Description: If set to true, MPI_ineighbor_alltoallw will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level ineighbor_alltoallw function will
        not be called.
    Default: 1

MPIR_CVAR_REDUCE_SCATTER_COMMUTATIVE_LONG_MSG_SIZE
    Aliases: MPIR_PARAM_REDUCE_SCATTER_COMMUTATIVE_LONG_MSG_SIZE
             MPICH_REDUCE_SCATTER_COMMUTATIVE_LONG_MSG_SIZE
    Description: the long message algorithm will be used if the operation
        is commutative and the send buffer size is >= this value (in bytes)
    Default: 524288

MPIR_CVAR_REDUCE_SCATTER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_REDUCE_SCATTER_INTRA_ALGORITHM
             MPICH_REDUCE_SCATTER_INTRA_ALGORITHM
    Description: Variable to select reduce_scatter algorithm
        auto               - Internal algorithm selection
        nb                 - Force nonblocking algorithm
        noncommutative     - Force noncommutative algorithm
        pairwise           - Force pairwise algorithm
        recursive_doubling - Force recursive doubling algorithm
        recursive_halving  - Force recursive halving algorithm
    Default: "auto"

MPIR_CVAR_REDUCE_SCATTER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_REDUCE_SCATTER_INTER_ALGORITHM
             MPICH_REDUCE_SCATTER_INTER_ALGORITHM
    Description: Variable to select reduce_scatter algorithm
        auto                        - Internal algorithm selection
        nb                          - Force nonblocking algorithm
        remote_reduce_local_scatter - Force remote-reduce-local-scatter
        algorithm
    Default: "auto"

MPIR_CVAR_REDUCE_SCATTER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_REDUCE_SCATTER_DEVICE_COLLECTIVE
             MPICH_REDUCE_SCATTER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Redscat will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level reduce_scatter function will not be called.
    Default: 1

MPIR_CVAR_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
             MPICH_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
    Description: Variable to select ineighbor_alltoallv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM
             MPICH_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM
    Description: Variable to select ineighbor_alltoallv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
             MPICH_INEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_ineighbor_alltoallv will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level ineighbor_alltoallv function will
        not be called.
    Default: 1

MPIR_CVAR_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
             MPICH_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
    Description: Variable to select neighbor_alltoallv algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM
             MPICH_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM
    Description: Variable to select neighbor_alltoallv algorithm
        auto - Internal algorithm selection
        nb   - Force nb algorithm
    Default: "auto"

MPIR_CVAR_NEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
             MPICH_NEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_neighbor_alltoallv will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level neighbor_alltoallv function will not
        be called.
    Default: 1

MPIR_CVAR_IBARRIER_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IBARRIER_RECEXCH_KVAL
             MPICH_IBARRIER_RECEXCH_KVAL
    Description: k value for recursive exchange based ibarrier
    Default: 2

MPIR_CVAR_IBARRIER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IBARRIER_INTRA_ALGORITHM
             MPICH_IBARRIER_INTRA_ALGORITHM
    Description: Variable to select ibarrier algorithm
        auto               - Internal algorithm selection
        recursive_doubling - Force recursive doubling algorithm
        recexch            - Force generic transport based recursive
        exchange algorithm
    Default: "auto"

MPIR_CVAR_IBARRIER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IBARRIER_INTER_ALGORITHM
             MPICH_IBARRIER_INTER_ALGORITHM
    Description: Variable to select ibarrier algorithm
        auto  - Internal algorithm selection
        bcast - Force bcast algorithm
    Default: "auto"

MPIR_CVAR_IBARRIER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IBARRIER_DEVICE_COLLECTIVE
             MPICH_IBARRIER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ibarrier will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level ibarrier function will not be called.
    Default: 1

MPIR_CVAR_BCAST_MIN_PROCS
    Aliases: MPIR_PARAM_BCAST_MIN_PROCS
             MPICH_BCAST_MIN_PROCS
    Description: Let's define short messages as messages with size <
        MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages
        with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but <
        MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with
        size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms
        selection procedure is as follows. For short messages or when the
        number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast
        using the binomial tree algorithm. Otherwise, for medium messages
        and with a power-of-two number of processes, we do broadcast based
        on a scatter followed by a recursive doubling allgather algorithm.
        Otherwise, for long messages or with non power-of-two number of
        processes, we do broadcast based on a scatter followed by a ring
        allgather algorithm. (See also: MPIR_CVAR_BCAST_SHORT_MSG_SIZE,
        MPIR_CVAR_BCAST_LONG_MSG_SIZE)
    Default: 8

MPIR_CVAR_BCAST_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_BCAST_SHORT_MSG_SIZE
             MPICH_BCAST_SHORT_MSG_SIZE
    Description: Let's define short messages as messages with size <
        MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages
        with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but <
        MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with
        size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms
        selection procedure is as follows. For short messages or when the
        number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast
        using the binomial tree algorithm. Otherwise, for medium messages
        and with a power-of-two number of processes, we do broadcast based
        on a scatter followed by a recursive doubling allgather algorithm.
        Otherwise, for long messages or with non power-of-two number of
        processes, we do broadcast based on a scatter followed by a ring
        allgather algorithm. (See also: MPIR_CVAR_BCAST_MIN_PROCS,
        MPIR_CVAR_BCAST_LONG_MSG_SIZE)
    Default: 12288

MPIR_CVAR_BCAST_LONG_MSG_SIZE
    Aliases: MPIR_PARAM_BCAST_LONG_MSG_SIZE
             MPICH_BCAST_LONG_MSG_SIZE
    Description: Let's define short messages as messages with size <
        MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages
        with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but <
        MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with
        size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms
        selection procedure is as follows. For short messages or when the
        number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast
        using the binomial tree algorithm. Otherwise, for medium messages
        and with a power-of-two number of processes, we do broadcast based
        on a scatter followed by a recursive doubling allgather algorithm.
        Otherwise, for long messages or with non power-of-two number of
        processes, we do broadcast based on a scatter followed by a ring
        allgather algorithm. (See also: MPIR_CVAR_BCAST_MIN_PROCS,
        MPIR_CVAR_BCAST_SHORT_MSG_SIZE)
    Default: 524288

MPIR_CVAR_ENABLE_SMP_BCAST
    Aliases: MPIR_PARAM_ENABLE_SMP_BCAST
             MPICH_ENABLE_SMP_BCAST
    Description: Enable SMP aware broadcast (See also:
        MPIR_CVAR_MAX_SMP_BCAST_MSG_SIZE)
    Default: 1

MPIR_CVAR_MAX_SMP_BCAST_MSG_SIZE
    Aliases: MPIR_PARAM_MAX_SMP_BCAST_MSG_SIZE
             MPICH_MAX_SMP_BCAST_MSG_SIZE
    Description: Maximum message size for which SMP-aware broadcast is
        used.  A value of '0' uses SMP-aware broadcast for all message
        sizes. (See also: MPIR_CVAR_ENABLE_SMP_BCAST)
    Default: 0

MPIR_CVAR_BCAST_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_BCAST_INTRA_ALGORITHM
             MPICH_BCAST_INTRA_ALGORITHM
    Description: Variable to select bcast algorithm
        auto                                    - Internal algorithm
        selection
        binomial                                - Force Binomial Tree
        nb                                      - Force nonblocking
        algorithm
        scatter_recursive_doubling_allgather    - Force Scatter
        Recursive-Doubling Allgather
        scatter_ring_allgather                  - Force Scatter Ring
    Default: "auto"

MPIR_CVAR_BCAST_INTER_ALGORITHM
    Aliases: MPIR_PARAM_BCAST_INTER_ALGORITHM
             MPICH_BCAST_INTER_ALGORITHM
    Description: Variable to select bcast algorithm
        auto                    - Internal algorithm selection
        nb                      - Force nonblocking algorithm
        remote_send_local_bcast - Force remote-send-local-bcast algorithm
    Default: "auto"

MPIR_CVAR_BCAST_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_BCAST_DEVICE_COLLECTIVE
             MPICH_BCAST_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Bcast will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually.  If set to
        false, the device-level bcast function will not be called.
    Default: 1

MPIR_CVAR_IGATHERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IGATHERV_INTRA_ALGORITHM
             MPICH_IGATHERV_INTRA_ALGORITHM
    Description: Variable to select igatherv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_IGATHERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IGATHERV_INTER_ALGORITHM
             MPICH_IGATHERV_INTER_ALGORITHM
    Description: Variable to select igatherv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_IGATHERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IGATHERV_DEVICE_COLLECTIVE
             MPICH_IGATHERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Igatherv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level igatherv function will not be called.
    Default: 1

MPIR_CVAR_IALLGATHERV_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IALLGATHERV_RECEXCH_KVAL
             MPICH_IALLGATHERV_RECEXCH_KVAL
    Description: k value for recursive exchange based iallgatherv
    Default: 2

MPIR_CVAR_IALLGATHERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IALLGATHERV_INTRA_ALGORITHM
             MPICH_IALLGATHERV_INTRA_ALGORITHM
    Description: Variable to select iallgatherv algorithm
        auto               - Internal algorithm selection
        brucks             - Force brucks algorithm
        recursive_doubling - Force recursive doubling algorithm
        ring               - Force ring algorithm
        recexch_distance_doubling    - Force generic transport recursive
        exchange with neighbours doubling in distance in each phase
        recexch_distance_halving     - Force generic transport recursive
        exchange with neighbours halving in distance in each phase
        gentran_ring              - Force generic transport ring algorithm
    Default: "auto"

MPIR_CVAR_IALLGATHERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IALLGATHERV_INTER_ALGORITHM
             MPICH_IALLGATHERV_INTER_ALGORITHM
    Description: Variable to select iallgatherv algorithm
        auto                      - Internal algorithm selection
        remote_gather_local_bcast - Force remote-gather-local-bcast
        algorithm
    Default: "auto"

MPIR_CVAR_IALLGATHERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IALLGATHERV_DEVICE_COLLECTIVE
             MPICH_IALLGATHERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iallgatherv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iallgatherv function will not be called.
    Default: 1

MPIR_CVAR_ISCAN_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ISCAN_INTRA_ALGORITHM
             MPICH_ISCAN_INTRA_ALGORITHM
    Description: Variable to select allgather algorithm
        auto               - Internal algorithm selection
        recursive_doubling - Force recursive doubling algorithm
    Default: "auto"

MPIR_CVAR_ISCAN_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ISCAN_DEVICE_COLLECTIVE
             MPICH_ISCAN_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iscan will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iscan function will not be called.
    Default: 1

MPIR_CVAR_SCAN_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_SCAN_INTRA_ALGORITHM
             MPICH_SCAN_INTRA_ALGORITHM
    Description: Variable to select allgather algorithm
        auto               - Internal algorithm selection
        nb                 - Force nonblocking algorithm
        recursive_doubling - Force recursive doubling algorithm
    Default: "auto"

MPIR_CVAR_SCAN_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_SCAN_DEVICE_COLLECTIVE
             MPICH_SCAN_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Scan will allow the device to override
        the MPIR-level collective algorithms. The device still has the
        option to call the MPIR-level algorithms manually. If set to false,
        the device-level scan function will not be called.
    Default: 1

MPIR_CVAR_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM
             MPICH_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM
    Description: Variable to select ineighbor_alltoall algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLTOALL_INTER_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALL_INTER_ALGORITHM
             MPICH_INEIGHBOR_ALLTOALL_INTER_ALGORITHM
    Description: Variable to select ineighbor_alltoall algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
             MPICH_INEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
    Description: If set to true, MPI_ineighbor_alltoall will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level ineighbor_alltoall function will not
        be called.
    Default: 1

MPIR_CVAR_REDUCE_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_REDUCE_SHORT_MSG_SIZE
             MPICH_REDUCE_SHORT_MSG_SIZE
    Description: the short message algorithm will be used if the send
        buffer size is <= this value (in bytes)
    Default: 2048

MPIR_CVAR_ENABLE_SMP_REDUCE
    Aliases: MPIR_PARAM_ENABLE_SMP_REDUCE
             MPICH_ENABLE_SMP_REDUCE
    Description: Enable SMP aware reduce.
    Default: 1

MPIR_CVAR_MAX_SMP_REDUCE_MSG_SIZE
    Aliases: MPIR_PARAM_MAX_SMP_REDUCE_MSG_SIZE
             MPICH_MAX_SMP_REDUCE_MSG_SIZE
    Description: Maximum message size for which SMP-aware reduce is used. 
        A value of '0' uses SMP-aware reduce for all message sizes.
    Default: 0

MPIR_CVAR_REDUCE_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_REDUCE_INTRA_ALGORITHM
             MPICH_REDUCE_INTRA_ALGORITHM
    Description: Variable to select reduce algorithm
        auto                  - Internal algorithm selection
        binomial              - Force binomial algorithm
        nb                    - Force nonblocking algorithm
        reduce_scatter_gather - Force reduce scatter gather algorithm
    Default: "auto"

MPIR_CVAR_REDUCE_INTER_ALGORITHM
    Aliases: MPIR_PARAM_REDUCE_INTER_ALGORITHM
             MPICH_REDUCE_INTER_ALGORITHM
    Description: Variable to select reduce algorithm
        auto                     - Internal algorithm selection
        local_reduce_remote_send - Force local-reduce-remote-send algorithm
        nb                       - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_REDUCE_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_REDUCE_DEVICE_COLLECTIVE
             MPICH_REDUCE_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Reduce will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level reduce function will not be called.
    Default: 1

MPIR_CVAR_ALLTOALLW_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ALLTOALLW_INTRA_ALGORITHM
             MPICH_ALLTOALLW_INTRA_ALGORITHM
    Description: Variable to select alltoallw algorithm
        auto                      - Internal algorithm selection
        nb                        - Force nonblocking algorithm
        pairwise_sendrecv_replace - Force pairwise sendrecv replace
        algorithm
        scattered                 - Force scattered algorithm
    Default: "auto"

MPIR_CVAR_ALLTOALLW_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ALLTOALLW_INTER_ALGORITHM
             MPICH_ALLTOALLW_INTER_ALGORITHM
    Description: Variable to select alltoallw algorithm
        auto              - Internal algorithm selection
        nb                - Force nonblocking algorithm
        pairwise_exchange - Force pairwise exchange algorithm
    Default: "auto"

MPIR_CVAR_ALLTOALLW_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ALLTOALLW_DEVICE_COLLECTIVE
             MPICH_ALLTOALLW_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Alltoallw will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level alltoallw function will not be called.
    Default: 1

MPIR_CVAR_ENABLE_SMP_BARRIER
    Aliases: MPIR_PARAM_ENABLE_SMP_BARRIER
             MPICH_ENABLE_SMP_BARRIER
    Description: Enable SMP aware barrier.
    Default: 1

MPIR_CVAR_BARRIER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_BARRIER_INTRA_ALGORITHM
             MPICH_BARRIER_INTRA_ALGORITHM
    Description: Variable to select barrier algorithm
        auto               - Internal algorithm selection
        nb                 - Force nonblocking algorithm
        recursive_doubling - Force recursive doubling algorithm
    Default: "auto"

MPIR_CVAR_BARRIER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_BARRIER_INTER_ALGORITHM
             MPICH_BARRIER_INTER_ALGORITHM
    Description: Variable to select barrier algorithm
        auto  - Internal algorithm selection
        bcast - Force bcast algorithm
        nb    - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_BARRIER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_BARRIER_DEVICE_COLLECTIVE
             MPICH_BARRIER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Barrier will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level barrier function will not be called.
    Default: 1

MPIR_CVAR_ISCATTERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_ISCATTERV_INTRA_ALGORITHM
             MPICH_ISCATTERV_INTRA_ALGORITHM
    Description: Variable to select iscatterv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_ISCATTERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_ISCATTERV_INTER_ALGORITHM
             MPICH_ISCATTERV_INTER_ALGORITHM
    Description: Variable to select iscatterv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_ISCATTERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_ISCATTERV_DEVICE_COLLECTIVE
             MPICH_ISCATTERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iscatterv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iscatterv function will not be called.
    Default: 1

MPIR_CVAR_DEVICE_COLLECTIVES
    Aliases: MPIR_PARAM_DEVICE_COLLECTIVES
             MPICH_DEVICE_COLLECTIVES
    Description: If set to true, MPI collectives will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually.  If set to
        false, the device-level collective function will not be called.
    Default: 1

MPIR_CVAR_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
             MPICH_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
    Description: Variable to select ineighbor_allgatherv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM
             MPICH_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM
    Description: Variable to select ineighbor_allgatherv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
             MPICH_INEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_ineighbor_allgatherv will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level ineighbor_allgatherv function will
        not be called.
    Default: 1

MPIR_CVAR_SCATTERV_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_SCATTERV_INTRA_ALGORITHM
             MPICH_SCATTERV_INTRA_ALGORITHM
    Description: Variable to select scatterv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
        nb     - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_SCATTERV_INTER_ALGORITHM
    Aliases: MPIR_PARAM_SCATTERV_INTER_ALGORITHM
             MPICH_SCATTERV_INTER_ALGORITHM
    Description: Variable to select scatterv algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
        nb     - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_SCATTERV_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_SCATTERV_DEVICE_COLLECTIVE
             MPICH_SCATTERV_DEVICE_COLLECTIVE
    Description: If set to true, MPI_scatterv will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level scatterv function will not be called.
    Default: 1

MPIR_CVAR_GATHER_VSMALL_MSG_SIZE
    Aliases: MPIR_PARAM_GATHER_VSMALL_MSG_SIZE
             MPICH_GATHER_VSMALL_MSG_SIZE
    Description: use a temporary buffer for intracommunicator MPI_Gather if
        the send buffer size is < this value (in bytes) (See also:
        MPIR_CVAR_GATHER_INTER_SHORT_MSG_SIZE)
    Default: 1024

MPIR_CVAR_GATHER_INTER_SHORT_MSG_SIZE
    Aliases: MPIR_PARAM_GATHER_INTER_SHORT_MSG_SIZE
             MPICH_GATHER_INTER_SHORT_MSG_SIZE
    Description: use the short message algorithm for intercommunicator
        MPI_Gather if the send buffer size is < this value (in bytes) (See
        also: MPIR_CVAR_GATHER_VSMALL_MSG_SIZE)
    Default: 2048

MPIR_CVAR_GATHER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_GATHER_INTRA_ALGORITHM
             MPICH_GATHER_INTRA_ALGORITHM
    Description: Variable to select gather algorithm
        auto     - Internal algorithm selection
        binomial - Force binomial algorithm
        nb       - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_GATHER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_GATHER_INTER_ALGORITHM
             MPICH_GATHER_INTER_ALGORITHM
    Description: Variable to select gather algorithm
        auto                     - Internal algorithm selection
        linear                   - Force linear algorithm
        local_gather_remote_send - Force local-gather-remote-send algorithm
        nb                       - Force nonblocking algorithm
    Default: "auto"

MPIR_CVAR_GATHER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_GATHER_DEVICE_COLLECTIVE
             MPICH_GATHER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Gather will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level gather function will not be called.
    Default: 1

MPIR_CVAR_IREDUCE_SCATTER_BLOCK_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_RECEXCH_KVAL
             MPICH_IREDUCE_SCATTER_BLOCK_RECEXCH_KVAL
    Description: k value for recursive exchange based ireduce_scatter_block
    Default: 2

MPIR_CVAR_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
             MPICH_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
    Description: Variable to select ireduce_scatter_block algorithm
        auto               - Internal algorithm selection
        noncommutative     - Force noncommutative algorithm
        recursive_doubling - Force recursive doubling algorithm
        pairwise           - Force pairwise algorithm
        recursive_halving  - Force recursive halving algorithm
        recexch  - Force generic transport recursive exchange algorithm
    Default: "auto"

MPIR_CVAR_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM
             MPICH_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM
    Description: Variable to select ireduce_scatter_block algorithm
        auto                         - Internal algorithm selection
        remote_reduce_local_scatterv - Force remote-reduce-local-scatterv
        algorithm
    Default: "auto"

MPIR_CVAR_IREDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
             MPICH_IREDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ireduce_scatter_block will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level ireduce_scatter_block function will
        not be called.
    Default: 1

MPIR_CVAR_IALLGATHER_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IALLGATHER_RECEXCH_KVAL
             MPICH_IALLGATHER_RECEXCH_KVAL
    Description: k value for recursive exchange based iallgather
    Default: 2

MPIR_CVAR_IALLGATHER_BRUCKS_KVAL
    Aliases: MPIR_PARAM_IALLGATHER_BRUCKS_KVAL
             MPICH_IALLGATHER_BRUCKS_KVAL
    Description: k value for radix in brucks based iallgather
    Default: 2

MPIR_CVAR_IALLGATHER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IALLGATHER_INTRA_ALGORITHM
             MPICH_IALLGATHER_INTRA_ALGORITHM
    Description: Variable to select iallgather algorithm
        auto               - Internal algorithm selection
        brucks             - Force brucks algorithm
        recursive_doubling - Force recursive doubling algorithm
        ring               - Force ring algorithm
        recexch_distance_doubling    - Force generic transport recursive
        exchange with neighbours doubling in distance in each phase
        recexch_distance_halving  - Force generic transport recursive
        exchange with neighbours halving in distance in each phase
        gentran_brucks     - Force generic transport based brucks algorithm
    Default: "auto"

MPIR_CVAR_IALLGATHER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IALLGATHER_INTER_ALGORITHM
             MPICH_IALLGATHER_INTER_ALGORITHM
    Description: Variable to select iallgather algorithm
        auto                      - Internal algorithm selection
        local_gather_remote_bcast - Force local-gather-remote-bcast
        algorithm
    Default: "auto"

MPIR_CVAR_IALLGATHER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IALLGATHER_DEVICE_COLLECTIVE
             MPICH_IALLGATHER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Iallgather will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually. If set to
        false, the device-level iallgather function will not be called.
    Default: 1

MPIR_CVAR_IBCAST_TREE_KVAL
    Aliases: MPIR_PARAM_IBCAST_TREE_KVAL
             MPICH_IBCAST_TREE_KVAL
    Description: k value for tree (kary, knomial, etc.) based ibcast
    Default: 2

MPIR_CVAR_IBCAST_TREE_TYPE
    Aliases: MPIR_PARAM_IBCAST_TREE_TYPE
             MPICH_IBCAST_TREE_TYPE
    Description: Tree type for tree based ibcast kary      - kary tree type
        knomial_1 - knomial_1 tree type knomial_2 - knomial_2 tree type
    Default: "kary"

MPIR_CVAR_IBCAST_TREE_PIPELINE_CHUNK_SIZE
    Aliases: MPIR_PARAM_IBCAST_TREE_PIPELINE_CHUNK_SIZE
             MPICH_IBCAST_TREE_PIPELINE_CHUNK_SIZE
    Description: Maximum chunk size (in bytes) for pipelining in tree based
        ibcast. Default value is 0, that is, no pipelining by default
    Default: 0

MPIR_CVAR_IBCAST_RING_CHUNK_SIZE
    Aliases: MPIR_PARAM_IBCAST_RING_CHUNK_SIZE
             MPICH_IBCAST_RING_CHUNK_SIZE
    Description: Maximum chunk size (in bytes) for pipelining in ibcast
        ring algorithm. Default value is 0, that is, no pipelining by
        default
    Default: 0

MPIR_CVAR_IBCAST_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_IBCAST_INTRA_ALGORITHM
             MPICH_IBCAST_INTRA_ALGORITHM
    Description: Variable to select ibcast algorithm
        auto                                 - Internal algorithm selection
        binomial                             - Force Binomial algorithm
        scatter_recursive_doubling_allgather - Force Scatter Recursive
        Doubling Allgather algorithm
        scatter_ring_allgather               - Force Scatter Ring Allgather
        algorithm
        tree                                 - Force Generic Transport Tree
        algorithm
        scatter_recexch_allgather            - Force Generic Transport
        Scatter followed by Recursive Exchange Allgather algorithm
        ring                                 - Force Generic Transport Ring
        algorithm
    Default: "auto"

MPIR_CVAR_IBCAST_SCATTER_KVAL
    Aliases: MPIR_PARAM_IBCAST_SCATTER_KVAL
             MPICH_IBCAST_SCATTER_KVAL
    Description: k value for tree based scatter in
        scatter_recexch_allgather algorithm
    Default: 2

MPIR_CVAR_IBCAST_ALLGATHER_RECEXCH_KVAL
    Aliases: MPIR_PARAM_IBCAST_ALLGATHER_RECEXCH_KVAL
             MPICH_IBCAST_ALLGATHER_RECEXCH_KVAL
    Description: k value for recursive exchange based allgather in
        scatter_recexch_allgather algorithm
    Default: 2

MPIR_CVAR_IBCAST_INTER_ALGORITHM
    Aliases: MPIR_PARAM_IBCAST_INTER_ALGORITHM
             MPICH_IBCAST_INTER_ALGORITHM
    Description: Variable to select ibcast algorithm
        auto - Internal algorithm selection
        flat - Force flat algorithm
    Default: "auto"

MPIR_CVAR_IBCAST_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_IBCAST_DEVICE_COLLECTIVE
             MPICH_IBCAST_DEVICE_COLLECTIVE
    Description: If set to true, MPI_Ibcast will allow the device to
        override the MPIR-level collective algorithms. The device still has
        the option to call the MPIR-level algorithms manually.  If set to
        false, the device-level ibcast function will not be called.
    Default: 1

MPIR_CVAR_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM
             MPICH_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM
    Description: Variable to select ineighbor_allgather algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLGATHER_INTER_ALGORITHM
    Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHER_INTER_ALGORITHM
             MPICH_INEIGHBOR_ALLGATHER_INTER_ALGORITHM
    Description: Variable to select ineighbor_allgather algorithm
        auto   - Internal algorithm selection
        linear - Force linear algorithm
    Default: "auto"

MPIR_CVAR_INEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
    Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
             MPICH_INEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
    Description: If set to true, MPI_ineighbor_allgather will allow the
        device to override the MPIR-level collective algorithms. The device
        still has the option to call the MPIR-level algorithms manually. If
        set to false, the device-level ineighbor_allgather function will
        not be called.
    Default: 1

MPIR_CVAR_MEMDUMP
    Aliases: MPIR_PARAM_MEMDUMP
             MPICH_MEMDUMP
    Description: If true, list any memory that was allocated by MPICH and
        that remains allocated when MPI_Finalize completes.
    Default: 1

MPIR_CVAR_MEM_CATEGORY_INFORMATION
    Aliases: MPIR_PARAM_MEM_CATEGORY_INFORMATION
             MPICH_MEM_CATEGORY_INFORMATION
    Description: If true, print a summary of memory allocation by category.
        The category definitions are found in mpl_trmem.h.
    Default: 0

MPIR_CVAR_DEBUG_HOLD
    Aliases: MPIR_PARAM_DEBUG_HOLD
             MPICH_DEBUG_HOLD
    Description: If true, causes processes to wait in MPI_Init and
        MPI_Initthread for a debugger to be attached.  Once the debugger
        has attached, the variable 'hold' should be set to 0 in order to
        allow the process to continue (e.g., in gdb, "set hold=0").
    Default: 0

MPIR_CVAR_ERROR_CHECKING
    Aliases: MPIR_PARAM_ERROR_CHECKING
             MPICH_ERROR_CHECKING
    Description: If true, perform checks for errors, typically to verify
        valid inputs to MPI routines.  Only effective when MPICH is
        configured with --enable-error-checking=runtime .
    Default: 1

MPIR_CVAR_NETLOC_NODE_FILE
    Aliases: MPIR_PARAM_NETLOC_NODE_FILE
             MPICH_NETLOC_NODE_FILE
    Description: Subnet json file
    Default: "auto"

MPIR_CVAR_SUPPRESS_ABORT_MESSAGE
    Aliases: MPIR_PARAM_SUPPRESS_ABORT_MESSAGE
             MPICH_SUPPRESS_ABORT_MESSAGE
    Description: Disable printing of abort error message.
    Default: 0

MPIR_CVAR_ASYNC_PROGRESS
    Aliases: MPIR_PARAM_ASYNC_PROGRESS
             MPICH_ASYNC_PROGRESS
    Description: If set to true, MPICH will initiate an additional thread
        to make asynchronous progress on all communication operations
        including point-to-point, collective, one-sided operations and I/O.
         Setting this variable will automatically increase the
        thread-safety level to MPI_THREAD_MULTIPLE.  While this improves
        the progress semantics, it might cause a small amount of
        performance overhead for regular MPI operations.  The user is
        encouraged to leave one or more hardware threads vacant in order to
        prevent contention between the application threads and the progress
        thread(s).  The impact of oversubscription is highly system
        dependent but may be substantial in some cases, hence this
        recommendation.
    Default: 0

MPIR_CVAR_DEFAULT_THREAD_LEVEL
    Aliases: MPIR_PARAM_DEFAULT_THREAD_LEVEL
             MPICH_DEFAULT_THREAD_LEVEL
    Description: Sets the default thread level to use when using MPI_INIT.
        This variable is case-insensitive.
    Default: "MPI_THREAD_SINGLE"

MPIR_CVAR_COMM_SPLIT_USE_QSORT
    Aliases: MPIR_PARAM_COMM_SPLIT_USE_QSORT
             MPICH_COMM_SPLIT_USE_QSORT
    Description: Use qsort(3) in the implementation of MPI_Comm_split
        instead of bubble sort.
    Default: 1

MPIR_CVAR_CTXID_EAGER_SIZE
    Aliases: MPIR_PARAM_CTXID_EAGER_SIZE
             MPICH_CTXID_EAGER_SIZE
    Description: The MPIR_CVAR_CTXID_EAGER_SIZE environment variable allows
        you to specify how many words in the context ID mask will be set
        aside for the eager allocation protocol.  If the application is
        running out of context IDs, reducing this value may help.
    Default: 2

MPIR_CVAR_PROCTABLE_SIZE
    Aliases: MPIR_PARAM_PROCTABLE_SIZE
             MPICH_PROCTABLE_SIZE
    Description: Size of the "MPIR" debugger interface proctable (process
        table).
    Default: 64

MPIR_CVAR_PROCTABLE_PRINT
    Aliases: MPIR_PARAM_PROCTABLE_PRINT
             MPICH_PROCTABLE_PRINT
    Description: If true, dump the proctable entries at
        MPII_Wait_for_debugger-time.
    Default: 0

MPIR_CVAR_NAMESERV_FILE_PUBDIR
    Aliases: MPIR_PARAM_NAMESERV_FILE_PUBDIR
             MPICH_NAMESERV_FILE_PUBDIR
             MPIR_CVAR_NAMEPUB_DIR
             MPIR_PARAM_NAMEPUB_DIR
             MPICH_NAMEPUB_DIR
    Description: Sets the directory to use for MPI service publishing in
        the file nameserv implementation.  Allows the user to override
        where the publish and lookup information is placed for
        connect/accept based applications.
    Default: NULL

MPIR_CVAR_ABORT_ON_LEAKED_HANDLES
    Aliases: MPIR_PARAM_ABORT_ON_LEAKED_HANDLES
             MPICH_ABORT_ON_LEAKED_HANDLES
    Description: If true, MPI will call MPI_Abort at MPI_Finalize if any
        MPI object handles have been leaked.  For example, if MPI_Comm_dup
        is called without calling a corresponding MPI_Comm_free.  For
        uninteresting reasons, enabling this option may prevent all known
        object leaks from being reported.  MPICH must have been configure
        with "--enable-g=handlealloc" or better in order for this
        functionality to work.
    Default: 0

MPIR_CVAR_NOLOCAL
    Aliases: MPIR_PARAM_NOLOCAL
             MPICH_NOLOCAL
             MPIR_CVAR_NO_LOCAL
             MPIR_PARAM_NO_LOCAL
             MPICH_NO_LOCAL
    Description: If true, force all processes to operate as though all
        processes are located on another node.  For example, this disables
        shared memory communication hierarchical collectives.
    Default: 0

MPIR_CVAR_ODD_EVEN_CLIQUES
    Aliases: MPIR_PARAM_ODD_EVEN_CLIQUES
             MPICH_ODD_EVEN_CLIQUES
             MPIR_CVAR_EVEN_ODD_CLIQUES
             MPIR_PARAM_EVEN_ODD_CLIQUES
             MPICH_EVEN_ODD_CLIQUES
    Description: If true, odd procs on a node are seen as local to each
        other, and even procs on a node are seen as local to each other. 
        Used for debugging on a single machine. Deprecated in favor of
        MPIR_CVAR_NUM_CLIQUES.
    Default: 0

MPIR_CVAR_NUM_CLIQUES
    Aliases: MPIR_PARAM_NUM_CLIQUES
             MPICH_NUM_CLIQUES
             MPIR_CVAR_NUM_CLIQUES
             MPIR_PARAM_NUM_CLIQUES
             MPICH_NUM_CLIQUES
    Description: Specify the number of cliques that should be used to
        partition procs on a local node. Procs with the same clique number
        are seen as local to each other. Used for debugging on a single
        machine.
    Default: 1

MPIR_CVAR_REQUEST_POLL_FREQ
    Aliases: MPIR_PARAM_REQUEST_POLL_FREQ
             MPICH_REQUEST_POLL_FREQ
    Description: How frequent to poll during completion calls (wait/test)
        in terms of number of processed requests before polling.
    Default: 8

MPIR_CVAR_REQUEST_BATCH_SIZE
    Aliases: MPIR_PARAM_REQUEST_BATCH_SIZE
             MPICH_REQUEST_BATCH_SIZE
    Description: The number of requests to make completion as a batch in
        MPI_Waitall and MPI_Testall implementation. A large number is
        likely to cause more cache misses.
    Default: 64

MPIR_CVAR_COLL_ALIAS_CHECK
    Aliases: MPIR_PARAM_COLL_ALIAS_CHECK
             MPICH_COLL_ALIAS_CHECK
    Description: Enable checking of aliasing in collective operations
    Default: 1

MPIR_CVAR_CH4_OFI_CAPABILITY_SETS_DEBUG
    Aliases: MPIR_PARAM_CH4_OFI_CAPABILITY_SETS_DEBUG
             MPICH_CH4_OFI_CAPABILITY_SETS_DEBUG
    Description: Prints out the configuration of each capability selected
        via the capability sets interface.
    Default: 0

MPIR_CVAR_CH4_OFI_ENABLE_DATA
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_DATA
             MPICH_CH4_OFI_ENABLE_DATA
    Description: Enable immediate data fields in OFI to transmit source
        rank outside of the match bits
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_AV_TABLE
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_AV_TABLE
             MPICH_CH4_OFI_ENABLE_AV_TABLE
    Description: If true, the OFI addressing information will be stored
        with an FI_AV_TABLE. If false, an FI_AV_MAP will be used.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_SCALABLE_ENDPOINTS
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_SCALABLE_ENDPOINTS
             MPICH_CH4_OFI_ENABLE_SCALABLE_ENDPOINTS
    Description: If true, use OFI scalable endpoints.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_SHARED_CONTEXTS
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_SHARED_CONTEXTS
             MPICH_CH4_OFI_ENABLE_SHARED_CONTEXTS
    Description: If set to false (zero), MPICH does not use OFI shared
        contexts. If set to -1, it is determined by the OFI capability sets
        based on the provider. Otherwise, MPICH tries to use OFI shared
        contexts. If they are unavailable, it'll fall back to the mode
        without shared contexts.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_MR_SCALABLE
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MR_SCALABLE
             MPICH_CH4_OFI_ENABLE_MR_SCALABLE
    Description: If true, MR_SCALABLE for OFI memory regions. If false,
        MR_BASIC for OFI memory regions.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_TAGGED
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_TAGGED
             MPICH_CH4_OFI_ENABLE_TAGGED
    Description: If true, use tagged message transmission functions in OFI.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_AM
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_AM
             MPICH_CH4_OFI_ENABLE_AM
    Description: If true, enable OFI active message support.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_RMA
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_RMA
             MPICH_CH4_OFI_ENABLE_RMA
    Description: If true, enable OFI RMA support.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_ATOMICS
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_ATOMICS
             MPICH_CH4_OFI_ENABLE_ATOMICS
    Description: If true, enable OFI Atomics support.
    Default: -1

MPIR_CVAR_CH4_OFI_FETCH_ATOMIC_IOVECS
    Aliases: MPIR_PARAM_CH4_OFI_FETCH_ATOMIC_IOVECS
             MPICH_CH4_OFI_FETCH_ATOMIC_IOVECS
    Description: Specifies the maximum number of iovecs that can be used by
        the OFI provider for fetch_atomic operations. The default value is
        -1, indicating that no value is set.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_DATA_AUTO_PROGRESS
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_DATA_AUTO_PROGRESS
             MPICH_CH4_OFI_ENABLE_DATA_AUTO_PROGRESS
    Description: If true, enable MPI data auto progress.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_CONTROL_AUTO_PROGRESS
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_CONTROL_AUTO_PROGRESS
             MPICH_CH4_OFI_ENABLE_CONTROL_AUTO_PROGRESS
    Description: If true, enable MPI control auto progress.
    Default: -1

MPIR_CVAR_CH4_OFI_ENABLE_PT2PT_NOPACK
    Aliases: MPIR_PARAM_CH4_OFI_ENABLE_PT2PT_NOPACK
             MPICH_CH4_OFI_ENABLE_PT2PT_NOPACK
    Description: If true, enable iovec for pt2pt.
    Default: -1

MPIR_CVAR_CH4_OFI_CONTEXT_ID_BITS
    Aliases: MPIR_PARAM_CH4_OFI_CONTEXT_ID_BITS
             MPICH_CH4_OFI_CONTEXT_ID_BITS
    Description: Specifies the number of bits that will be used for
        matching the context ID. The default value is -1, indicating that
        no value is set and that the default will be defined in the
        ofi_types.h file.
    Default: -1

MPIR_CVAR_CH4_OFI_RANK_BITS
    Aliases: MPIR_PARAM_CH4_OFI_RANK_BITS
             MPICH_CH4_OFI_RANK_BITS
    Description: Specifies the number of bits that will be used for
        matching the MPI rank. The default value is -1, indicating that no
        value is set and that the default will be defined in the
        ofi_types.h file.
    Default: -1

MPIR_CVAR_CH4_OFI_TAG_BITS
    Aliases: MPIR_PARAM_CH4_OFI_TAG_BITS
             MPICH_CH4_OFI_TAG_BITS
    Description: Specifies the number of bits that will be used for
        matching the user tag. The default value is -1, indicating that no
        value is set and that the default will be defined in the
        ofi_types.h file.
    Default: -1

MPIR_CVAR_CH4_OFI_MAJOR_VERSION
    Aliases: MPIR_PARAM_CH4_OFI_MAJOR_VERSION
             MPICH_CH4_OFI_MAJOR_VERSION
    Description: Specifies the major version of the OFI library. The
        default is the major version of the OFI library used with MPICH. If
        using this CVAR, it is recommended that the user also specifies a
        specific OFI provider.
    Default: -1

MPIR_CVAR_CH4_OFI_MINOR_VERSION
    Aliases: MPIR_PARAM_CH4_OFI_MINOR_VERSION
             MPICH_CH4_OFI_MINOR_VERSION
    Description: Specifies the major version of the OFI library. The
        default is the minor version of the OFI library used with MPICH. If
        using this CVAR, it is recommended that the user also specifies a
        specific OFI provider.
    Default: -1

MPIR_CVAR_CH4_OFI_MAX_VNIS
    Aliases: MPIR_PARAM_CH4_OFI_MAX_VNIS
             MPICH_CH4_OFI_MAX_VNIS
    Description: If set to positive, this CVAR specifies the maximum number
        of CH4 VNIs that OFI netmod exposes.
    Default: 1

MPIR_CVAR_CH4_OFI_MAX_RMA_SEP_CTX
    Aliases: MPIR_PARAM_CH4_OFI_MAX_RMA_SEP_CTX
             MPICH_CH4_OFI_MAX_RMA_SEP_CTX
    Description: If set to positive, this CVAR specifies the maximum number
        of transmit contexts RMA can utilize in a scalable endpoint. This
        value is effective only when scalable endpoint is available,
        otherwise it will be ignored.
    Default: 0

MPIR_CVAR_CH4_OFI_MAX_EAGAIN_RETRY
    Aliases: MPIR_PARAM_CH4_OFI_MAX_EAGAIN_RETRY
             MPICH_CH4_OFI_MAX_EAGAIN_RETRY
    Description: If set to positive, this CVAR specifies the maximum number
        of retries of an ofi operations before returning MPIX_ERR_EAGAIN.
        This value is effective only when the communicator has the
        MPI_OFI_set_eagain info hint set to true.
    Default: -1

MPIR_CVAR_CH4_OFI_NUM_AM_BUFFERS
    Aliases: MPIR_PARAM_CH4_OFI_NUM_AM_BUFFERS
             MPICH_CH4_OFI_NUM_AM_BUFFERS
    Description: Specifies the number of buffers for receiving active
        messages.
    Default: -1

MPIR_CVAR_CH4_COMM_CONNECT_TIMEOUT
    Aliases: MPIR_PARAM_CH4_COMM_CONNECT_TIMEOUT
             MPICH_CH4_COMM_CONNECT_TIMEOUT
    Description: The default time out period in seconds for a connection
        attempt to the server communicator where the named port exists but
        no pending accept. User can change the value for a specified
        connection through its info argument.
    Default: 180

MPIR_CVAR_CH4_RMA_MEM_EFFICIENT
    Aliases: MPIR_PARAM_CH4_RMA_MEM_EFFICIENT
             MPICH_CH4_RMA_MEM_EFFICIENT
    Description: If true, memory-saving mode is on, per-target object is
        released at the epoch end call. If false, performance-efficient
        mode is on, all allocated target objects are cached and freed at
        win_finalize.
    Default: 0

MPIR_CVAR_CH4_NETMOD
    Aliases: MPIR_PARAM_CH4_NETMOD
             MPICH_CH4_NETMOD
    Description: If non-empty, this cvar specifies which network module to
        use
    Default: ""

MPIR_CVAR_CH4_SHM
    Aliases: MPIR_PARAM_CH4_SHM
             MPICH_CH4_SHM
    Description: If non-empty, this cvar specifies which shm module to use
    Default: ""

MPIR_CVAR_CH4_ROOTS_ONLY_PMI
    Aliases: MPIR_PARAM_CH4_ROOTS_ONLY_PMI
             MPICH_CH4_ROOTS_ONLY_PMI
    Description: Enables an optimized business card exchange over PMI for
        node root processes only.
    Default: 0

MPIR_CVAR_CH4_RUNTIME_CONF_DEBUG
    Aliases: MPIR_PARAM_CH4_RUNTIME_CONF_DEBUG
             MPICH_CH4_RUNTIME_CONF_DEBUG
    Description: If enabled, CH4-level runtime configurations are printed
        out
    Default: 0

MPIR_CVAR_CH4_MT_MODEL
    Aliases: MPIR_PARAM_CH4_MT_MODEL
             MPICH_CH4_MT_MODEL
    Description: Specifies the CH4 multi-threading model. Possible values
        are: direct (default) handoff trylock
    Default: ""

MPIR_CVAR_CH4_RANDOM_ADDR_RETRY
    Aliases: MPIR_PARAM_CH4_RANDOM_ADDR_RETRY
             MPICH_CH4_RANDOM_ADDR_RETRY
    Description: The default number of retries for generating a random
        address. A retrying involves only local operations.
    Default: 100

MPIR_CVAR_CH4_SHM_SYMHEAP_RETRY
    Aliases: MPIR_PARAM_CH4_SHM_SYMHEAP_RETRY
             MPICH_CH4_SHM_SYMHEAP_RETRY
    Description: The default number of retries for allocating a symmetric
        heap in shared memory. A retrying involves collective communication
        over the group in the shared memory.
    Default: 100

MPIR_CVAR_ENABLE_HCOLL
    Aliases: MPIR_PARAM_ENABLE_HCOLL
             MPICH_ENABLE_HCOLL
    Description: Enable hcoll collective support.
    Default: 0

MPIR_CVAR_COLL_SCHED_DUMP
    Aliases: MPIR_PARAM_COLL_SCHED_DUMP
             MPICH_COLL_SCHED_DUMP
    Description: Print schedule data for nonblocking collective operations.
    Default: 0

MPIR_CVAR_OFI_USE_PROVIDER
    Aliases: MPIR_PARAM_OFI_USE_PROVIDER
             MPICH_OFI_USE_PROVIDER
    Description: If non-null, choose an OFI provider by name. If using with
        the CH4 device and using a provider that supports an older version
        of the libfabric API then the default version of the installed
        library, specifying the OFI version via the appropriate CVARs is
        also recommended.
    Default: NULL

MPIR_CVAR_OFI_DUMP_PROVIDERS
    Aliases: MPIR_PARAM_OFI_DUMP_PROVIDERS
             MPICH_OFI_DUMP_PROVIDERS
    Description: If true, dump provider information at init
    Default: 0

MPIR_CVAR_NEMESIS_MXM_BULK_CONNECT
    Aliases: MPIR_PARAM_NEMESIS_MXM_BULK_CONNECT
             MPICH_NEMESIS_MXM_BULK_CONNECT
    Description: If true, force mxm to connect all processes at
        initialization time.
    Default: 0

MPIR_CVAR_NEMESIS_MXM_BULK_DISCONNECT
    Aliases: MPIR_PARAM_NEMESIS_MXM_BULK_DISCONNECT
             MPICH_NEMESIS_MXM_BULK_DISCONNECT
    Description: If true, force mxm to disconnect all processes at
        finalization time.
    Default: 0

MPIR_CVAR_NEMESIS_MXM_HUGEPAGE
    Aliases: MPIR_PARAM_NEMESIS_MXM_HUGEPAGE
             MPICH_NEMESIS_MXM_HUGEPAGE
    Description: If true, mxm tries detecting hugepage support.  On HPC-X
        2.3 and earlier, this might cause problems on Ubuntu and other
        platforms even if the system provides hugepage support.
    Default: 0

MPIR_CVAR_CH3_INTERFACE_HOSTNAME
    Aliases: MPIR_PARAM_CH3_INTERFACE_HOSTNAME
             MPICH_CH3_INTERFACE_HOSTNAME
             MPIR_CVAR_INTERFACE_HOSTNAME
             MPIR_PARAM_INTERFACE_HOSTNAME
             MPICH_INTERFACE_HOSTNAME
    Description: If non-NULL, this cvar specifies the IP address that other
        processes should use when connecting to this process. This cvar is
        mutually exclusive with the MPIR_CVAR_CH3_NETWORK_IFACE cvar and it
        is an error to set them both.
    Default: NULL

MPIR_CVAR_CH3_PORT_RANGE
    Aliases: MPIR_PARAM_CH3_PORT_RANGE
             MPICH_CH3_PORT_RANGE
             MPIR_CVAR_PORTRANGE
             MPIR_CVAR_PORT_RANGE
             MPIR_PARAM_PORTRANGE
             MPIR_PARAM_PORT_RANGE
             MPICH_PORTRANGE
             MPICH_PORT_RANGE
    Description: The MPIR_CVAR_CH3_PORT_RANGE environment variable allows
        you to specify the range of TCP ports to be used by the process
        manager and the MPICH library. The format of this variable is
        <low>:<high>.  To specify any available port, use 0:0.
    Default: {0,0}

MPIR_CVAR_NEMESIS_TCP_NETWORK_IFACE
    Aliases: MPIR_PARAM_NEMESIS_TCP_NETWORK_IFACE
             MPICH_NEMESIS_TCP_NETWORK_IFACE
             MPIR_CVAR_NETWORK_IFACE
             MPIR_PARAM_NETWORK_IFACE
             MPICH_NETWORK_IFACE
    Description: If non-NULL, this cvar specifies which pseudo-ethernet
        interface the tcp netmod should use (e.g., "eth1", "ib0"). Note,
        this is a Linux-specific cvar. This cvar is mutually exclusive with
        the MPIR_CVAR_CH3_INTERFACE_HOSTNAME cvar and it is an error to set
        them both.
    Default: NULL

MPIR_CVAR_NEMESIS_TCP_HOST_LOOKUP_RETRIES
    Aliases: MPIR_PARAM_NEMESIS_TCP_HOST_LOOKUP_RETRIES
             MPICH_NEMESIS_TCP_HOST_LOOKUP_RETRIES
    Description: This cvar controls the number of times to retry the
        gethostbyname() function before giving up.
    Default: 10

MPIR_CVAR_POLLS_BEFORE_YIELD
    Aliases: MPIR_PARAM_POLLS_BEFORE_YIELD
             MPICH_POLLS_BEFORE_YIELD
    Description: When MPICH is in a busy waiting loop, it will periodically
        call a function to yield the processor.  This cvar sets the number
        of loops before the yield function is called.  A value of 0
        disables yielding.
    Default: 1000

MPIR_CVAR_NEMESIS_NETMOD
    Aliases: MPIR_PARAM_NEMESIS_NETMOD
             MPICH_NEMESIS_NETMOD
    Description: If non-empty, this cvar specifies which network module
        should be used for communication. This variable is
        case-insensitive.
    Default: ""

MPIR_CVAR_NEMESIS_SHM_EAGER_MAX_SZ
    Aliases: MPIR_PARAM_NEMESIS_SHM_EAGER_MAX_SZ
             MPICH_NEMESIS_SHM_EAGER_MAX_SZ
    Description: This cvar controls the message size at which Nemesis
        switches from eager to rendezvous mode for shared memory. If this
        cvar is set to -1, then Nemesis will choose an appropriate value.
    Default: -1

MPIR_CVAR_NEMESIS_SHM_READY_EAGER_MAX_SZ
    Aliases: MPIR_PARAM_NEMESIS_SHM_READY_EAGER_MAX_SZ
             MPICH_NEMESIS_SHM_READY_EAGER_MAX_SZ
    Description: This cvar controls the message size at which Nemesis
        switches from eager to rendezvous mode for ready-send messages.  If
        this cvar is set to -1, then ready messages will always be sent
        eagerly.  If this cvar is set to -2, then Nemesis will choose an
        appropriate value.
    Default: -2

MPIR_CVAR_NEMESIS_ENABLE_CKPOINT
    Aliases: MPIR_PARAM_NEMESIS_ENABLE_CKPOINT
             MPICH_NEMESIS_ENABLE_CKPOINT
    Description: If true, enables checkpointing support and returns an
        error if checkpointing library cannot be initialized.
    Default: 0

MPIR_CVAR_NEMESIS_LMT_DMA_THRESHOLD
    Aliases: MPIR_PARAM_NEMESIS_LMT_DMA_THRESHOLD
             MPICH_NEMESIS_LMT_DMA_THRESHOLD
    Description: Messages larger than this size will use the "dma" (knem)
        intranode LMT implementation, if it is enabled and available.
    Default: 2097152

MPIR_CVAR_ENABLE_FT
    Aliases: MPIR_PARAM_ENABLE_FT
             MPICH_ENABLE_FT
    Description: Enable fault tolerance functions
    Default: 0

MPIR_CVAR_CH3_RMA_SCALABLE_FENCE_PROCESS_NUM
    Aliases: MPIR_PARAM_CH3_RMA_SCALABLE_FENCE_PROCESS_NUM
             MPICH_CH3_RMA_SCALABLE_FENCE_PROCESS_NUM
    Description: Specify the threshold of switching the algorithm used in
        FENCE from the basic algorithm to the scalable algorithm. The value
        can be nagative, zero or positive. When the number of processes is
        larger than or equal to this value, FENCE will use a scalable
        algorithm which do not use O(P) data structure; when the number of
        processes is smaller than the value, FENCE will use a basic but
        fast algorithm which requires an O(P) data structure.
    Default: 1024

MPIR_CVAR_CH3_RMA_DELAY_ISSUING_FOR_PIGGYBACKING
    Aliases: MPIR_PARAM_CH3_RMA_DELAY_ISSUING_FOR_PIGGYBACKING
             MPICH_CH3_RMA_DELAY_ISSUING_FOR_PIGGYBACKING
    Description: Specify if delay issuing of RMA operations for
        piggybacking LOCK/UNLOCK/FLUSH is enabled. It can be either 0 or 1.
        When it is set to 1, the issuing of LOCK message is delayed until
        origin process see the first RMA operation and piggyback LOCK with
        that operation, and the origin process always keeps the current
        last operation until the ending synchronization call in order to
        piggyback UNLOCK/FLUSH with that operation. When it is set to 0, in
        WIN_LOCK/UNLOCK case, the LOCK message is sent out as early as
        possible, in WIN_LOCK_ALL/UNLOCK_ALL case, the origin process still
        tries to piggyback LOCK message with the first operation; for
        UNLOCK/FLUSH message, the origin process no longer keeps the
        current last operation but only piggyback UNLOCK/FLUSH if there is
        an operation avaliable in the ending synchronization call.
    Default: 0

MPIR_CVAR_CH3_EAGER_MAX_MSG_SIZE
    Aliases: MPIR_PARAM_CH3_EAGER_MAX_MSG_SIZE
             MPICH_CH3_EAGER_MAX_MSG_SIZE
    Description: This cvar controls the message size at which CH3 switches
        from eager to rendezvous mode.
    Default: 131072

MPIR_CVAR_CH3_RMA_SLOTS_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_SLOTS_SIZE
             MPICH_CH3_RMA_SLOTS_SIZE
    Description: Number of RMA slots during window creation. Each slot
        contains a linked list of target elements. The distribution of
        ranks among slots follows a round-robin pattern. Requires a
        positive value.
    Default: 262144

MPIR_CVAR_CH3_RMA_TARGET_LOCK_DATA_BYTES
    Aliases: MPIR_PARAM_CH3_RMA_TARGET_LOCK_DATA_BYTES
             MPICH_CH3_RMA_TARGET_LOCK_DATA_BYTES
    Description: Size (in bytes) of available lock data this window can
        provided. If current buffered lock data is more than this value,
        the process will drop the upcoming operation data. Requires a
        positive calue.
    Default: 655360

MPIR_CVAR_CH3_RMA_OP_WIN_POOL_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_OP_WIN_POOL_SIZE
             MPICH_CH3_RMA_OP_WIN_POOL_SIZE
    Description: Size of the window-private RMA operations pool (in number
        of operations) that stores information about RMA operations that
        could not be issued immediately.  Requires a positive value.
    Default: 256

MPIR_CVAR_CH3_RMA_OP_GLOBAL_POOL_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_OP_GLOBAL_POOL_SIZE
             MPICH_CH3_RMA_OP_GLOBAL_POOL_SIZE
    Description: Size of the Global RMA operations pool (in number of
        operations) that stores information about RMA operations that could
        not be issued immediatly.  Requires a positive value.
    Default: 16384

MPIR_CVAR_CH3_RMA_TARGET_WIN_POOL_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_TARGET_WIN_POOL_SIZE
             MPICH_CH3_RMA_TARGET_WIN_POOL_SIZE
    Description: Size of the window-private RMA target pool (in number of
        targets) that stores information about RMA targets that could not
        be issued immediately.  Requires a positive value.
    Default: 256

MPIR_CVAR_CH3_RMA_TARGET_GLOBAL_POOL_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_TARGET_GLOBAL_POOL_SIZE
             MPICH_CH3_RMA_TARGET_GLOBAL_POOL_SIZE
    Description: Size of the Global RMA targets pool (in number of targets)
        that stores information about RMA targets that could not be issued
        immediatly.  Requires a positive value.
    Default: 16384

MPIR_CVAR_CH3_RMA_TARGET_LOCK_ENTRY_WIN_POOL_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_TARGET_LOCK_ENTRY_WIN_POOL_SIZE
             MPICH_CH3_RMA_TARGET_LOCK_ENTRY_WIN_POOL_SIZE
    Description: Size of the window-private RMA lock entries pool (in
        number of lock entries) that stores information about RMA lock
        requests that could not be satisfied immediatly.  Requires a
        positive value.
    Default: 256

MPIR_CVAR_CH3_RMA_ACTIVE_REQ_THRESHOLD
    Aliases: MPIR_PARAM_CH3_RMA_ACTIVE_REQ_THRESHOLD
             MPICH_CH3_RMA_ACTIVE_REQ_THRESHOLD
    Description: Threshold of number of active requests to trigger blocking
        waiting in operation routines. When the value is negative, we never
        blockingly wait in operation routines. When the value is zero, we
        always trigger blocking waiting in operation routines to wait until
        no. of active requests becomes zero. When the value is positive, we
        do blocking waiting in operation routines to wait until no. of
        active requests being reduced to this value.
    Default: 65536

MPIR_CVAR_CH3_RMA_POKE_PROGRESS_REQ_THRESHOLD
    Aliases: MPIR_PARAM_CH3_RMA_POKE_PROGRESS_REQ_THRESHOLD
             MPICH_CH3_RMA_POKE_PROGRESS_REQ_THRESHOLD
    Description: Threshold at which the RMA implementation attempts to
        complete requests while completing RMA operations and while using
        the lazy synchonization approach.  Change this value if programs
        fail because they run out of requests or other internal resources
    Default: 128

MPIR_CVAR_CH3_ENABLE_HCOLL
    Aliases: MPIR_PARAM_CH3_ENABLE_HCOLL
             MPICH_CH3_ENABLE_HCOLL
    Description: If true, enable HCOLL collectives.
    Default: 0

MPIR_CVAR_CH3_COMM_CONNECT_TIMEOUT
    Aliases: MPIR_PARAM_CH3_COMM_CONNECT_TIMEOUT
             MPICH_CH3_COMM_CONNECT_TIMEOUT
    Description: The default time out period in seconds for a connection
        attempt to the server communicator where the named port exists but
        no pending accept. User can change the value for a specified
        connection through its info argument.
    Default: 180

MPIR_CVAR_CH3_RMA_OP_PIGGYBACK_LOCK_DATA_SIZE
    Aliases: MPIR_PARAM_CH3_RMA_OP_PIGGYBACK_LOCK_DATA_SIZE
             MPICH_CH3_RMA_OP_PIGGYBACK_LOCK_DATA_SIZE
    Description: Specify the threshold of data size of a RMA operation
        which can be piggybacked with a LOCK message. It is always a
        positive value and should not be smaller than
        MPIDI_RMA_IMMED_BYTES. If user sets it as a small value, for middle
        and large data size, we will lose performance because of always
        waiting for round-trip of LOCK synchronization; if user sets it as
        a large value, we need to consume more memory on target side to
        buffer this lock request when lock is not satisfied.
    Default: 65536