Commit | Line | Data |
---|---|---|
2866c82d | 1 | /* |
da751ca9 JA |
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. | |
2866c82d JA |
6 | * |
7 | */ | |
8 | #include <stdio.h> | |
9 | #include <stdlib.h> | |
10 | #include <unistd.h> | |
11 | #include <errno.h> | |
2866c82d | 12 | #include <sys/mman.h> |
5f350952 JA |
13 | |
14 | #include "../fio.h" | |
2866c82d | 15 | |
ac893112 JA |
16 | /* |
17 | * Limits us to 2GB of mapped files in total | |
18 | */ | |
19 | #define MMAP_TOTAL_SZ (2 * 1024 * 1024 * 1024UL) | |
2866c82d | 20 | |
ac893112 JA |
21 | static unsigned long mmap_map_size; |
22 | static unsigned long mmap_map_mask; | |
2866c82d | 23 | |
ac893112 JA |
24 | static int fio_mmap_file(struct thread_data *td, struct fio_file *f, |
25 | size_t length, off_t off) | |
b5af8293 | 26 | { |
ac893112 JA |
27 | int flags = 0; |
28 | int ret = 0; | |
c97d8369 | 29 | |
b5af8293 JA |
30 | if (td_rw(td)) |
31 | flags = PROT_READ | PROT_WRITE; | |
32 | else if (td_write(td)) { | |
33 | flags = PROT_WRITE; | |
34 | ||
2dc1bbeb | 35 | if (td->o.verify != VERIFY_NONE) |
b5af8293 JA |
36 | flags |= PROT_READ; |
37 | } else | |
38 | flags = PROT_READ; | |
39 | ||
ac893112 JA |
40 | f->mmap_ptr = mmap(NULL, length, flags, MAP_SHARED, f->fd, off); |
41 | if (f->mmap_ptr == MAP_FAILED) { | |
8de43fd2 JA |
42 | int err = errno; |
43 | ||
ac893112 | 44 | f->mmap_ptr = NULL; |
8de43fd2 | 45 | td_verror(td, err, "mmap"); |
b5af8293 JA |
46 | goto err; |
47 | } | |
48 | ||
49 | if (file_invalidate_cache(td, f)) | |
50 | goto err; | |
51 | ||
52 | if (!td_random(td)) { | |
ac893112 | 53 | if (madvise(f->mmap_ptr, length, MADV_SEQUENTIAL) < 0) { |
b5af8293 JA |
54 | td_verror(td, errno, "madvise"); |
55 | goto err; | |
56 | } | |
57 | } else { | |
ac893112 | 58 | if (madvise(f->mmap_ptr, length, MADV_RANDOM) < 0) { |
b5af8293 JA |
59 | td_verror(td, errno, "madvise"); |
60 | goto err; | |
61 | } | |
62 | } | |
63 | ||
b5af8293 | 64 | err: |
ac893112 | 65 | return ret; |
b5af8293 JA |
66 | } |
67 | ||
ac893112 | 68 | static int fio_mmapio_prep(struct thread_data *td, struct io_u *io_u) |
b5af8293 | 69 | { |
ac893112 JA |
70 | struct fio_file *f = io_u->file; |
71 | int ret = 0; | |
6977bcd0 | 72 | |
ac893112 JA |
73 | if (io_u->buflen > mmap_map_size) { |
74 | log_err("fio: bs too big for mmap engine\n"); | |
75 | ret = EIO; | |
76 | goto err; | |
77 | } | |
78 | ||
79 | if (io_u->offset >= f->mmap_off && | |
80 | io_u->offset + io_u->buflen < f->mmap_off + f->mmap_sz) | |
81 | goto done; | |
6977bcd0 | 82 | |
ac893112 JA |
83 | if (f->mmap_ptr) { |
84 | if (munmap(f->mmap_ptr, f->mmap_sz) < 0) { | |
85 | ret = errno; | |
86 | goto err; | |
87 | } | |
88 | f->mmap_ptr = NULL; | |
b5af8293 | 89 | } |
6977bcd0 | 90 | |
ac893112 JA |
91 | f->mmap_sz = mmap_map_size; |
92 | if (f->mmap_sz > f->io_size) | |
93 | f->mmap_sz = f->io_size; | |
6977bcd0 | 94 | |
ac893112 JA |
95 | f->mmap_off = io_u->offset & ~mmap_map_mask; |
96 | if (io_u->offset + io_u->buflen >= f->mmap_off + f->mmap_sz) | |
97 | f->mmap_off -= io_u->buflen; | |
98 | ||
99 | ret = fio_mmap_file(td, f, f->mmap_sz, f->mmap_off); | |
100 | done: | |
101 | if (!ret) | |
102 | io_u->mmap_data = f->mmap_ptr + io_u->offset - f->mmap_off - | |
103 | f->file_offset; | |
104 | err: | |
6977bcd0 | 105 | return ret; |
b5af8293 JA |
106 | } |
107 | ||
ac893112 JA |
108 | static int fio_mmapio_queue(struct thread_data *td, struct io_u *io_u) |
109 | { | |
110 | struct fio_file *f = io_u->file; | |
111 | ||
112 | fio_ro_check(td, io_u); | |
113 | ||
114 | if (io_u->ddir == DDIR_READ) | |
115 | memcpy(io_u->xfer_buf, io_u->mmap_data, io_u->xfer_buflen); | |
116 | else if (io_u->ddir == DDIR_WRITE) | |
117 | memcpy(io_u->mmap_data, io_u->xfer_buf, io_u->xfer_buflen); | |
118 | else if (io_u->ddir == DDIR_SYNC) { | |
119 | if (msync(f->mmap_ptr, f->mmap_sz, MS_SYNC)) { | |
120 | io_u->error = errno; | |
121 | td_verror(td, io_u->error, "msync"); | |
122 | } | |
123 | } | |
124 | ||
125 | /* | |
126 | * not really direct, but should drop the pages from the cache | |
127 | */ | |
128 | if (td->o.odirect && io_u->ddir != DDIR_SYNC) { | |
129 | if (msync(io_u->mmap_data, io_u->xfer_buflen, MS_SYNC) < 0) { | |
130 | io_u->error = errno; | |
131 | td_verror(td, io_u->error, "msync"); | |
132 | } | |
133 | if (madvise(io_u->mmap_data, io_u->xfer_buflen, MADV_DONTNEED) < 0) { | |
134 | io_u->error = errno; | |
135 | td_verror(td, io_u->error, "madvise"); | |
136 | } | |
137 | } | |
138 | ||
139 | return FIO_Q_COMPLETED; | |
140 | } | |
141 | ||
142 | static int fio_mmapio_init(struct thread_data *td) | |
143 | { | |
144 | unsigned long shift, mask; | |
145 | ||
146 | mmap_map_size = MMAP_TOTAL_SZ / td->o.nr_files; | |
147 | mask = mmap_map_size; | |
148 | shift = 0; | |
149 | do { | |
150 | mask >>= 1; | |
151 | if (!mask) | |
152 | break; | |
153 | shift++; | |
154 | } while (1); | |
155 | ||
156 | mmap_map_mask = 1UL << shift; | |
157 | return 0; | |
158 | } | |
159 | ||
5f350952 | 160 | static struct ioengine_ops ioengine = { |
2866c82d JA |
161 | .name = "mmap", |
162 | .version = FIO_IOOPS_VERSION, | |
ac893112 JA |
163 | .init = fio_mmapio_init, |
164 | .prep = fio_mmapio_prep, | |
2866c82d | 165 | .queue = fio_mmapio_queue, |
ac893112 JA |
166 | .open_file = generic_open_file, |
167 | .close_file = generic_close_file, | |
df9c26b1 | 168 | .get_file_size = generic_get_file_size, |
0263882a | 169 | .flags = FIO_SYNCIO | FIO_NOEXTEND, |
2866c82d | 170 | }; |
5f350952 JA |
171 | |
172 | static void fio_init fio_mmapio_register(void) | |
173 | { | |
174 | register_ioengine(&ioengine); | |
175 | } | |
176 | ||
177 | static void fio_exit fio_mmapio_unregister(void) | |
178 | { | |
179 | unregister_ioengine(&ioengine); | |
180 | } |