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
|
/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
*
* Copyright (C) 1997 University of Chicago.
* See COPYRIGHT notice in top-level directory.
*/
#include "ad_xfs.h"
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
/* style: allow:free:2 sig:0 */
static void ADIOI_XFS_Aligned_Mem_File_Read(ADIO_File fd, void *buf, int len,
ADIO_Offset offset, int *err);
void ADIOI_XFS_ReadContig(ADIO_File fd, void *buf, int count,
MPI_Datatype datatype, int file_ptr_type,
ADIO_Offset offset, ADIO_Status *status, int *error_code)
{
int diff, size, nbytes;
MPI_Count err=-1, datatype_size, len;
void *newbuf;
static char myname[] = "ADIOI_XFS_READCONTIG";
MPI_Type_size_x(datatype, &datatype_size);
len = datatype_size * count;
fd->fp_sys_posn = -1; /* set it to null, since we are using pread */
if (file_ptr_type == ADIO_INDIVIDUAL) offset = fd->fp_ind;
if (!(fd->direct_read)) /* direct I/O not enabled */
err = pread(fd->fd_sys, buf, len, offset);
else { /* direct I/O enabled */
/* (1) if mem_aligned && file_aligned
use direct I/O to read up to correct io_size
use buffered I/O for remaining */
if (!(((long) buf) % fd->d_mem) && !(offset % fd->d_miniosz))
ADIOI_XFS_Aligned_Mem_File_Read(fd, buf, len, offset, &err);
/* (2) if !file_aligned
use buffered I/O to read up to file_aligned
At that point, if still mem_aligned, use (1)
else copy into aligned buf and then use (1) */
else if (offset % fd->d_miniosz) {
diff = fd->d_miniosz - (offset % fd->d_miniosz);
diff = ADIOI_MIN(diff, len);
nbytes = pread(fd->fd_sys, buf, diff, offset);
buf = ((char *) buf) + diff;
offset += diff;
size = len - diff;
if (!(((long) buf) % fd->d_mem)) {
ADIOI_XFS_Aligned_Mem_File_Read(fd, buf, size, offset, &err);
nbytes += err;
}
else {
newbuf = (void *) memalign(XFS_MEMALIGN, size);
if (newbuf) {
ADIOI_XFS_Aligned_Mem_File_Read(fd, newbuf, size, offset, &err);
if (err > 0) memcpy(buf, newbuf, err);
nbytes += err;
ADIOI_Free(newbuf);
}
else nbytes += pread(fd->fd_sys, buf, size, offset);
}
err = nbytes;
}
/* (3) if !mem_aligned && file_aligned
copy into aligned buf, then use (1) */
else {
newbuf = (void *) memalign(XFS_MEMALIGN, len);
if (newbuf) {
ADIOI_XFS_Aligned_Mem_File_Read(fd, newbuf, len, offset, &err);
if (err > 0) memcpy(buf, newbuf, err);
ADIOI_Free(newbuf);
}
else err = pread(fd->fd_sys, buf, len, offset);
}
}
if (file_ptr_type == ADIO_INDIVIDUAL) fd->fp_ind += err;
#ifdef HAVE_STATUS_SET_BYTES
if (err != -1) MPIR_Status_set_bytes(status, datatype, err);
#endif
if (err == -1) {
*error_code = MPIO_Err_create_code(MPI_SUCCESS, MPIR_ERR_RECOVERABLE,
myname, __LINE__, MPI_ERR_IO, "**io",
"**io %s", strerror(errno));
}
else *error_code = MPI_SUCCESS;
}
void ADIOI_XFS_Aligned_Mem_File_Read(ADIO_File fd, void *buf, int len,
ADIO_Offset offset, int *err)
{
int ntimes, rem, newrem, i, size, nbytes;
unsigned read_chunk_sz = fd->hints->fs_hints.xfs.read_chunk_sz;
/* memory buffer is aligned, offset in file is aligned,
io_size may or may not be of the right size.
use direct I/O to read up to correct io_size,
use buffered I/O for remaining. */
if (!(len % fd->d_miniosz) &&
(len >= fd->d_miniosz) && (len <= read_chunk_sz))
*err = pread(fd->fd_direct, buf, len, offset);
else if (len < fd->d_miniosz)
*err = pread(fd->fd_sys, buf, len, offset);
else if (len > read_chunk_sz) {
ntimes = len/(read_chunk_sz);
rem = len - ntimes * read_chunk_sz;
nbytes = 0;
for (i=0; i<ntimes; i++) {
nbytes += pread(fd->fd_direct, ((char *)buf) + i * read_chunk_sz,
read_chunk_sz, offset);
offset += read_chunk_sz;
}
if (rem) {
if (!(rem % fd->d_miniosz))
nbytes += pread(fd->fd_direct,
((char *)buf) + ntimes * read_chunk_sz, rem, offset);
else {
newrem = rem % fd->d_miniosz;
size = rem - newrem;
if (size) {
nbytes += pread(fd->fd_direct,
((char *)buf) + ntimes * read_chunk_sz, size, offset);
offset += size;
}
nbytes += pread(fd->fd_sys,
((char *)buf) + ntimes * read_chunk_sz + size, newrem, offset);
}
}
*err = nbytes;
}
else {
rem = len % fd->d_miniosz;
size = len - rem;
nbytes = pread(fd->fd_direct, buf, size, offset);
nbytes += pread(fd->fd_sys, (char *)buf + size, rem, offset+size);
*err = nbytes;
}
}
|
