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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <fcntl.h>
#include <string.h>
#include <assert.h>
#include "ioshark.h"
#include "ioshark_bench.h"
/*
* The purpose of this code is to convert mmap() calls into
* a mix of (semi)-random reads and writes.
* PROT_READ => 4KB/8KB/16KB random reads.
* PROT_WRITE => adds 4KB random writes.
*/
extern char *progname;
#define IOSHARK_MAX_MMAP_IOLEN (16*1024)
#define MMAP_ENTS 16
struct mmap_io_ent_tab_s {
off_t offset;
size_t len;
};
struct mmap_io_ent_s {
int num_entries;
struct mmap_io_ent_tab_s table[MMAP_ENTS + 1];
size_t resid;
};
static void
setup_mmap_io_state(struct mmap_io_ent_s *mio,
size_t total_len, off_t offset)
{
int slice;
memset(mio, 0, sizeof(struct mmap_io_ent_s));
mio->resid = total_len;
slice = MAX(IOSHARK_MAX_MMAP_IOLEN,
total_len / MMAP_ENTS);
while (total_len > 0) {
assert(mio->num_entries < MMAP_ENTS + 1);
mio->table[mio->num_entries].offset = offset;
mio->table[mio->num_entries].len =
MIN((u_int64_t)total_len, (u_int64_t)slice);
total_len -= mio->table[mio->num_entries].len;
offset += mio->table[mio->num_entries].len;
mio->num_entries++;
}
}
static size_t
mmap_getnext_off_len(struct mmap_io_ent_s *mio,
off_t *offset)
{
int i;
int find_rand_index[MMAP_ENTS + 1];
int rand_index_len = 0;
size_t iolength;
if (mio->resid == 0)
return 0;
/* Pick a slot with residual length > 0 at random first */
for (i = 0 ; i < MMAP_ENTS + 1 ; i++) {
if (mio->table[i].len > 0)
find_rand_index[rand_index_len++] = i;
}
i = find_rand_index[rand() % rand_index_len];
/* Randomize iolength 4K-16K */
iolength = ((rand() % 4) + 1) * 4096;
iolength = MIN(mio->table[i].len, iolength);
*offset = mio->table[i].offset;
mio->table[i].offset += iolength;
mio->table[i].len -= iolength;
mio->resid -= iolength;
return iolength;
}
static void
mmap_do_io(void *db_node, int prot, off_t offset, size_t len,
char **bufp, int *buflen, u_int64_t *op_counts,
struct rw_bytes_s *rw_bytes)
{
char *p;
int ret;
if (!(prot & IOSHARK_PROT_WRITE)) {
/* Only preads */
p = get_buf(bufp, buflen, len, 0);
ret = pread(files_db_get_fd(db_node),
p, len, offset);
rw_bytes->bytes_read += len;
if (ret < 0) {
fprintf(stderr,
"%s: mapped pread(%s %zu %lu) error fd=%d %s\n",
progname, files_db_get_filename(db_node),
len, offset, files_db_get_fd(db_node),
strerror(errno));
exit(EXIT_FAILURE);
}
op_counts[IOSHARK_MAPPED_PREAD]++;
} else {
/* 50-50 R/W */
if ((rand() % 2) == 1) {
p = get_buf(bufp, buflen, len, 1);
ret = pwrite(files_db_get_fd(db_node),
p, len, offset);
rw_bytes->bytes_written += len;
if (ret < 0) {
#if 0
fprintf(stderr,
"%s: mapped pwrite failed, file unwriteable ? open_flags=%x\n",
progname,
fcntl(files_db_get_fd(db_node), F_GETFL));
exit(EXIT_FAILURE);
#endif
} else
op_counts[IOSHARK_MAPPED_PWRITE]++;
} else {
p = get_buf(bufp, buflen, len, 0);
ret = pread(files_db_get_fd(db_node),
p, len, offset);
rw_bytes->bytes_read += len;
if (ret < 0) {
fprintf(stderr,
"%s: mapped pread(%s %zu %lu) error fd=%d %s\n",
progname, files_db_get_filename(db_node),
len,
offset, files_db_get_fd(db_node),
strerror(errno));
exit(EXIT_FAILURE);
}
op_counts[IOSHARK_MAPPED_PREAD]++;
}
}
}
void
ioshark_handle_mmap(void *db_node,
struct ioshark_file_operation *file_op,
char **bufp, int *buflen, u_int64_t *op_counts,
struct rw_bytes_s *rw_bytes)
{
off_t offset = file_op->mmap_offset;
size_t len = file_op->mmap_len;
int prot = file_op->mmap_prot;
struct mmap_io_ent_s mio;
struct stat statbuf;
if (fstat(files_db_get_fd(db_node), &statbuf) < 0) {
fprintf(stderr,
"%s: fstat failure %s\n",
__func__, strerror(errno));
exit(EXIT_FAILURE);
}
/*
* The size of the file better accomodate offset + len
* Else there is an issue with pre-creation
*/
assert(offset + len <= statbuf.st_size);
if (len <= IOSHARK_MAX_MMAP_IOLEN) {
mmap_do_io(db_node, prot, offset, len,
bufp, buflen, op_counts,
rw_bytes);
return;
}
setup_mmap_io_state(&mio, len, offset);
assert(mio.num_entries > 0);
while ((len = mmap_getnext_off_len(&mio, &offset))) {
assert((offset + len) <=
(file_op->mmap_offset + file_op->mmap_len));
mmap_do_io(db_node, prot, offset, len, bufp, buflen,
op_counts, rw_bytes);
}
}
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