summaryrefslogtreecommitdiff
path: root/engines/mmap.c
blob: 9dbefc8214dd71d7dc569864d7c571f7391fc5d7 (plain)
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
/*
 * mmap engine
 *
 * IO engine that reads/writes from files by doing memcpy to/from
 * a memory mapped region of the file.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/mman.h>

#include "../fio.h"
#include "../verify.h"

/*
 * Limits us to 1GiB of mapped files in total
 */
#define MMAP_TOTAL_SZ	(1 * 1024 * 1024 * 1024UL)

static unsigned long mmap_map_size;

struct fio_mmap_data {
	void *mmap_ptr;
	size_t mmap_sz;
	off_t mmap_off;
};

static bool fio_madvise_file(struct thread_data *td, struct fio_file *f,
			     size_t length)

{
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);

	if (!td->o.fadvise_hint)
		return true;

	if (!td_random(td)) {
		if (posix_madvise(fmd->mmap_ptr, length, POSIX_MADV_SEQUENTIAL) < 0) {
			td_verror(td, errno, "madvise");
			return false;
		}
	} else {
		if (posix_madvise(fmd->mmap_ptr, length, POSIX_MADV_RANDOM) < 0) {
			td_verror(td, errno, "madvise");
			return false;
		}
	}

	return true;
}

static int fio_mmap_file(struct thread_data *td, struct fio_file *f,
			 size_t length, off_t off)
{
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
	int flags = 0;

	if (td_rw(td) && !td->o.verify_only)
		flags = PROT_READ | PROT_WRITE;
	else if (td_write(td) && !td->o.verify_only) {
		flags = PROT_WRITE;

		if (td->o.verify != VERIFY_NONE)
			flags |= PROT_READ;
	} else
		flags = PROT_READ;

	fmd->mmap_ptr = mmap(NULL, length, flags, MAP_SHARED, f->fd, off);
	if (fmd->mmap_ptr == MAP_FAILED) {
		fmd->mmap_ptr = NULL;
		td_verror(td, errno, "mmap");
		goto err;
	}

	if (!fio_madvise_file(td, f, length))
		goto err;

	if (posix_madvise(fmd->mmap_ptr, length, POSIX_MADV_DONTNEED) < 0) {
		td_verror(td, errno, "madvise");
		goto err;
	}

#ifdef FIO_MADV_FREE
	if (f->filetype == FIO_TYPE_BLOCK)
		(void) posix_madvise(fmd->mmap_ptr, fmd->mmap_sz, FIO_MADV_FREE);
#endif

err:
	if (td->error && fmd->mmap_ptr)
		munmap(fmd->mmap_ptr, length);

	return td->error;
}

/*
 * Just mmap an appropriate portion, we cannot mmap the full extent
 */
static int fio_mmapio_prep_limited(struct thread_data *td, struct io_u *io_u)
{
	struct fio_file *f = io_u->file;
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);

	if (io_u->buflen > mmap_map_size) {
		log_err("fio: bs too big for mmap engine\n");
		return EIO;
	}

	fmd->mmap_sz = mmap_map_size;
	if (fmd->mmap_sz  > f->io_size)
		fmd->mmap_sz = f->io_size;

	fmd->mmap_off = io_u->offset;

	return fio_mmap_file(td, f, fmd->mmap_sz, fmd->mmap_off);
}

/*
 * Attempt to mmap the entire file
 */
static int fio_mmapio_prep_full(struct thread_data *td, struct io_u *io_u)
{
	struct fio_file *f = io_u->file;
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
	int ret;

	if (fio_file_partial_mmap(f))
		return EINVAL;
	if (io_u->offset != (size_t) io_u->offset ||
	    f->io_size != (size_t) f->io_size) {
		fio_file_set_partial_mmap(f);
		return EINVAL;
	}

	fmd->mmap_sz = f->io_size;
	fmd->mmap_off = 0;

	ret = fio_mmap_file(td, f, fmd->mmap_sz, fmd->mmap_off);
	if (ret)
		fio_file_set_partial_mmap(f);

	return ret;
}

static int fio_mmapio_prep(struct thread_data *td, struct io_u *io_u)
{
	struct fio_file *f = io_u->file;
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);
	int ret;

	/*
	 * It fits within existing mapping, use it
	 */
	if (io_u->offset >= fmd->mmap_off &&
	    io_u->offset + io_u->buflen <= fmd->mmap_off + fmd->mmap_sz)
		goto done;

	/*
	 * unmap any existing mapping
	 */
	if (fmd->mmap_ptr) {
		if (munmap(fmd->mmap_ptr, fmd->mmap_sz) < 0)
			return errno;
		fmd->mmap_ptr = NULL;
	}

	if (fio_mmapio_prep_full(td, io_u)) {
		td_clear_error(td);
		ret = fio_mmapio_prep_limited(td, io_u);
		if (ret)
			return ret;
	}

done:
	io_u->mmap_data = fmd->mmap_ptr + io_u->offset - fmd->mmap_off -
				f->file_offset;
	return 0;
}

static int fio_mmapio_queue(struct thread_data *td, struct io_u *io_u)
{
	struct fio_file *f = io_u->file;
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);

	fio_ro_check(td, io_u);

	if (io_u->ddir == DDIR_READ)
		memcpy(io_u->xfer_buf, io_u->mmap_data, io_u->xfer_buflen);
	else if (io_u->ddir == DDIR_WRITE)
		memcpy(io_u->mmap_data, io_u->xfer_buf, io_u->xfer_buflen);
	else if (ddir_sync(io_u->ddir)) {
		if (msync(fmd->mmap_ptr, fmd->mmap_sz, MS_SYNC)) {
			io_u->error = errno;
			td_verror(td, io_u->error, "msync");
		}
	} else if (io_u->ddir == DDIR_TRIM) {
		int ret = do_io_u_trim(td, io_u);

		if (!ret)
			td_verror(td, io_u->error, "trim");
	}


	/*
	 * not really direct, but should drop the pages from the cache
	 */
	if (td->o.odirect && ddir_rw(io_u->ddir)) {
		if (msync(io_u->mmap_data, io_u->xfer_buflen, MS_SYNC) < 0) {
			io_u->error = errno;
			td_verror(td, io_u->error, "msync");
		}
		if (posix_madvise(io_u->mmap_data, io_u->xfer_buflen, POSIX_MADV_DONTNEED) < 0) {
			io_u->error = errno;
			td_verror(td, io_u->error, "madvise");
		}
	}

	return FIO_Q_COMPLETED;
}

static int fio_mmapio_init(struct thread_data *td)
{
	struct thread_options *o = &td->o;

	if ((o->rw_min_bs & page_mask) &&
	    (o->odirect || o->fsync_blocks || o->fdatasync_blocks)) {
		log_err("fio: mmap options dictate a minimum block size of "
			"%llu bytes\n", (unsigned long long) page_size);
		return 1;
	}

	mmap_map_size = MMAP_TOTAL_SZ / o->nr_files;
	return 0;
}

static int fio_mmapio_open_file(struct thread_data *td, struct fio_file *f)
{
	struct fio_mmap_data *fmd;
	int ret;

	ret = generic_open_file(td, f);
	if (ret)
		return ret;

	fmd = calloc(1, sizeof(*fmd));
	if (!fmd) {
		int fio_unused __ret;
		__ret = generic_close_file(td, f);
		return 1;
	}

	FILE_SET_ENG_DATA(f, fmd);
	return 0;
}

static int fio_mmapio_close_file(struct thread_data *td, struct fio_file *f)
{
	struct fio_mmap_data *fmd = FILE_ENG_DATA(f);

	FILE_SET_ENG_DATA(f, NULL);
	free(fmd);
	fio_file_clear_partial_mmap(f);

	return generic_close_file(td, f);
}

static struct ioengine_ops ioengine = {
	.name		= "mmap",
	.version	= FIO_IOOPS_VERSION,
	.init		= fio_mmapio_init,
	.prep		= fio_mmapio_prep,
	.queue		= fio_mmapio_queue,
	.open_file	= fio_mmapio_open_file,
	.close_file	= fio_mmapio_close_file,
	.get_file_size	= generic_get_file_size,
	.flags		= FIO_SYNCIO | FIO_NOEXTEND,
};

static void fio_init fio_mmapio_register(void)
{
	register_ioengine(&ioengine);
}

static void fio_exit fio_mmapio_unregister(void)
{
	unregister_ioengine(&ioengine);
}