Some more bits of blktrace support
[fio.git] / engines / mmap.c
CommitLineData
2866c82d 1/*
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2 * mmap engine
3 *
4 * IO engine that reads/writes from files by doing memcpy to/from
5 * a memory mapped region of the file.
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6 *
7 */
8#include <stdio.h>
9#include <stdlib.h>
10#include <unistd.h>
11#include <errno.h>
12#include <assert.h>
13#include <sys/mman.h>
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14
15#include "../fio.h"
2866c82d 16
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17static int fio_mmapio_queue(struct thread_data *td, struct io_u *io_u)
18{
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19 struct fio_file *f = io_u->file;
20 unsigned long long real_off = io_u->offset - f->file_offset;
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21
22 if (io_u->ddir == DDIR_READ)
cec6b55d 23 memcpy(io_u->xfer_buf, f->mmap + real_off, io_u->xfer_buflen);
87dc1ab1 24 else if (io_u->ddir == DDIR_WRITE)
cec6b55d 25 memcpy(f->mmap + real_off, io_u->xfer_buf, io_u->xfer_buflen);
b907a5b5 26 else if (io_u->ddir == DDIR_SYNC) {
7bb48f84 27 size_t len = (f->io_size + page_size - 1) & ~page_mask;
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28
29 if (msync(f->mmap, len, MS_SYNC)) {
b907a5b5 30 io_u->error = errno;
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31 td_verror(td, io_u->error, "msync");
32 }
b907a5b5 33 }
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34
35 /*
36 * not really direct, but should drop the pages from the cache
37 */
2dc1bbeb 38 if (td->o.odirect && io_u->ddir != DDIR_SYNC) {
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39 size_t len = (io_u->xfer_buflen + page_size - 1) & ~page_mask;
40 unsigned long long off = real_off & ~page_mask;
41
42 if (msync(f->mmap + off, len, MS_SYNC) < 0) {
2866c82d 43 io_u->error = errno;
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44 td_verror(td, io_u->error, "msync");
45 }
46 if (madvise(f->mmap + off, len, MADV_DONTNEED) < 0) {
2866c82d 47 io_u->error = errno;
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48 td_verror(td, io_u->error, "madvise");
49 }
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50 }
51
36167d82 52 return FIO_Q_COMPLETED;
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53}
54
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55static int fio_mmapio_open(struct thread_data *td, struct fio_file *f)
56{
57 int ret, flags;
58
59 ret = generic_open_file(td, f);
60 if (ret)
61 return ret;
62
63 if (td_rw(td))
64 flags = PROT_READ | PROT_WRITE;
65 else if (td_write(td)) {
66 flags = PROT_WRITE;
67
2dc1bbeb 68 if (td->o.verify != VERIFY_NONE)
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69 flags |= PROT_READ;
70 } else
71 flags = PROT_READ;
72
7bb48f84 73 f->mmap = mmap(NULL, f->io_size, flags, MAP_SHARED, f->fd, f->file_offset);
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74 if (f->mmap == MAP_FAILED) {
75 f->mmap = NULL;
76 td_verror(td, errno, "mmap");
77 goto err;
78 }
79
80 if (file_invalidate_cache(td, f))
81 goto err;
82
83 if (!td_random(td)) {
7bb48f84 84 if (madvise(f->mmap, f->io_size, MADV_SEQUENTIAL) < 0) {
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85 td_verror(td, errno, "madvise");
86 goto err;
87 }
88 } else {
7bb48f84 89 if (madvise(f->mmap, f->io_size, MADV_RANDOM) < 0) {
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90 td_verror(td, errno, "madvise");
91 goto err;
92 }
93 }
94
95 return 0;
96
97err:
0263882a 98 td->io_ops->close_file(td, f);
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99 return 1;
100}
101
102static void fio_mmapio_close(struct thread_data fio_unused *td,
103 struct fio_file *f)
104{
105 if (f->mmap) {
7bb48f84 106 munmap(f->mmap, f->io_size);
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107 f->mmap = NULL;
108 }
0263882a 109 generic_close_file(td, f);
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110}
111
5f350952 112static struct ioengine_ops ioengine = {
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113 .name = "mmap",
114 .version = FIO_IOOPS_VERSION,
2866c82d 115 .queue = fio_mmapio_queue,
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116 .open_file = fio_mmapio_open,
117 .close_file = fio_mmapio_close,
0263882a 118 .flags = FIO_SYNCIO | FIO_NOEXTEND,
2866c82d 119};
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120
121static void fio_init fio_mmapio_register(void)
122{
123 register_ioengine(&ioengine);
124}
125
126static void fio_exit fio_mmapio_unregister(void)
127{
128 unregister_ioengine(&ioengine);
129}