xref: /linux/tools/perf/util/mmap.c (revision eed4edda910fe34dfae8c6bfbcf57f4593a54295)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2011-2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
4  *
5  * Parts came from evlist.c builtin-{top,stat,record}.c, see those files for further
6  * copyright notes.
7  */
8 
9 #include <sys/mman.h>
10 #include <inttypes.h>
11 #include <asm/bug.h>
12 #include <linux/zalloc.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <unistd.h> // sysconf()
16 #include <perf/mmap.h>
17 #ifdef HAVE_LIBNUMA_SUPPORT
18 #include <numaif.h>
19 #endif
20 #include "cpumap.h"
21 #include "debug.h"
22 #include "event.h"
23 #include "mmap.h"
24 #include "../perf.h"
25 #include <internal/lib.h> /* page_size */
26 #include <linux/bitmap.h>
27 
28 #define MASK_SIZE 1023
29 void mmap_cpu_mask__scnprintf(struct mmap_cpu_mask *mask, const char *tag)
30 {
31 	char buf[MASK_SIZE + 1];
32 	size_t len;
33 
34 	len = bitmap_scnprintf(mask->bits, mask->nbits, buf, MASK_SIZE);
35 	buf[len] = '\0';
36 	pr_debug("%p: %s mask[%zd]: %s\n", mask, tag, mask->nbits, buf);
37 }
38 
39 size_t mmap__mmap_len(struct mmap *map)
40 {
41 	return perf_mmap__mmap_len(&map->core);
42 }
43 
44 int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused,
45 			       struct auxtrace_mmap_params *mp __maybe_unused,
46 			       void *userpg __maybe_unused,
47 			       int fd __maybe_unused)
48 {
49 	return 0;
50 }
51 
52 void __weak auxtrace_mmap__munmap(struct auxtrace_mmap *mm __maybe_unused)
53 {
54 }
55 
56 void __weak auxtrace_mmap_params__init(struct auxtrace_mmap_params *mp __maybe_unused,
57 				       off_t auxtrace_offset __maybe_unused,
58 				       unsigned int auxtrace_pages __maybe_unused,
59 				       bool auxtrace_overwrite __maybe_unused)
60 {
61 }
62 
63 void __weak auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp __maybe_unused,
64 					  struct evlist *evlist __maybe_unused,
65 					  struct evsel *evsel __maybe_unused,
66 					  int idx __maybe_unused)
67 {
68 }
69 
70 #ifdef HAVE_AIO_SUPPORT
71 static int perf_mmap__aio_enabled(struct mmap *map)
72 {
73 	return map->aio.nr_cblocks > 0;
74 }
75 
76 #ifdef HAVE_LIBNUMA_SUPPORT
77 static int perf_mmap__aio_alloc(struct mmap *map, int idx)
78 {
79 	map->aio.data[idx] = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE,
80 				  MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
81 	if (map->aio.data[idx] == MAP_FAILED) {
82 		map->aio.data[idx] = NULL;
83 		return -1;
84 	}
85 
86 	return 0;
87 }
88 
89 static void perf_mmap__aio_free(struct mmap *map, int idx)
90 {
91 	if (map->aio.data[idx]) {
92 		munmap(map->aio.data[idx], mmap__mmap_len(map));
93 		map->aio.data[idx] = NULL;
94 	}
95 }
96 
97 static int perf_mmap__aio_bind(struct mmap *map, int idx, struct perf_cpu cpu, int affinity)
98 {
99 	void *data;
100 	size_t mmap_len;
101 	unsigned long *node_mask;
102 	unsigned long node_index;
103 	int err = 0;
104 
105 	if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) {
106 		data = map->aio.data[idx];
107 		mmap_len = mmap__mmap_len(map);
108 		node_index = cpu__get_node(cpu);
109 		node_mask = bitmap_zalloc(node_index + 1);
110 		if (!node_mask) {
111 			pr_err("Failed to allocate node mask for mbind: error %m\n");
112 			return -1;
113 		}
114 		__set_bit(node_index, node_mask);
115 		if (mbind(data, mmap_len, MPOL_BIND, node_mask, node_index + 1 + 1, 0)) {
116 			pr_err("Failed to bind [%p-%p] AIO buffer to node %lu: error %m\n",
117 				data, data + mmap_len, node_index);
118 			err = -1;
119 		}
120 		bitmap_free(node_mask);
121 	}
122 
123 	return err;
124 }
125 #else /* !HAVE_LIBNUMA_SUPPORT */
126 static int perf_mmap__aio_alloc(struct mmap *map, int idx)
127 {
128 	map->aio.data[idx] = malloc(mmap__mmap_len(map));
129 	if (map->aio.data[idx] == NULL)
130 		return -1;
131 
132 	return 0;
133 }
134 
135 static void perf_mmap__aio_free(struct mmap *map, int idx)
136 {
137 	zfree(&(map->aio.data[idx]));
138 }
139 
140 static int perf_mmap__aio_bind(struct mmap *map __maybe_unused, int idx __maybe_unused,
141 		struct perf_cpu cpu __maybe_unused, int affinity __maybe_unused)
142 {
143 	return 0;
144 }
145 #endif
146 
147 static int perf_mmap__aio_mmap(struct mmap *map, struct mmap_params *mp)
148 {
149 	int delta_max, i, prio, ret;
150 
151 	map->aio.nr_cblocks = mp->nr_cblocks;
152 	if (map->aio.nr_cblocks) {
153 		map->aio.aiocb = calloc(map->aio.nr_cblocks, sizeof(struct aiocb *));
154 		if (!map->aio.aiocb) {
155 			pr_debug2("failed to allocate aiocb for data buffer, error %m\n");
156 			return -1;
157 		}
158 		map->aio.cblocks = calloc(map->aio.nr_cblocks, sizeof(struct aiocb));
159 		if (!map->aio.cblocks) {
160 			pr_debug2("failed to allocate cblocks for data buffer, error %m\n");
161 			return -1;
162 		}
163 		map->aio.data = calloc(map->aio.nr_cblocks, sizeof(void *));
164 		if (!map->aio.data) {
165 			pr_debug2("failed to allocate data buffer, error %m\n");
166 			return -1;
167 		}
168 		delta_max = sysconf(_SC_AIO_PRIO_DELTA_MAX);
169 		for (i = 0; i < map->aio.nr_cblocks; ++i) {
170 			ret = perf_mmap__aio_alloc(map, i);
171 			if (ret == -1) {
172 				pr_debug2("failed to allocate data buffer area, error %m");
173 				return -1;
174 			}
175 			ret = perf_mmap__aio_bind(map, i, map->core.cpu, mp->affinity);
176 			if (ret == -1)
177 				return -1;
178 			/*
179 			 * Use cblock.aio_fildes value different from -1
180 			 * to denote started aio write operation on the
181 			 * cblock so it requires explicit record__aio_sync()
182 			 * call prior the cblock may be reused again.
183 			 */
184 			map->aio.cblocks[i].aio_fildes = -1;
185 			/*
186 			 * Allocate cblocks with priority delta to have
187 			 * faster aio write system calls because queued requests
188 			 * are kept in separate per-prio queues and adding
189 			 * a new request will iterate thru shorter per-prio
190 			 * list. Blocks with numbers higher than
191 			 *  _SC_AIO_PRIO_DELTA_MAX go with priority 0.
192 			 */
193 			prio = delta_max - i;
194 			map->aio.cblocks[i].aio_reqprio = prio >= 0 ? prio : 0;
195 		}
196 	}
197 
198 	return 0;
199 }
200 
201 static void perf_mmap__aio_munmap(struct mmap *map)
202 {
203 	int i;
204 
205 	for (i = 0; i < map->aio.nr_cblocks; ++i)
206 		perf_mmap__aio_free(map, i);
207 	if (map->aio.data)
208 		zfree(&map->aio.data);
209 	zfree(&map->aio.cblocks);
210 	zfree(&map->aio.aiocb);
211 }
212 #else /* !HAVE_AIO_SUPPORT */
213 static int perf_mmap__aio_enabled(struct mmap *map __maybe_unused)
214 {
215 	return 0;
216 }
217 
218 static int perf_mmap__aio_mmap(struct mmap *map __maybe_unused,
219 			       struct mmap_params *mp __maybe_unused)
220 {
221 	return 0;
222 }
223 
224 static void perf_mmap__aio_munmap(struct mmap *map __maybe_unused)
225 {
226 }
227 #endif
228 
229 void mmap__munmap(struct mmap *map)
230 {
231 	bitmap_free(map->affinity_mask.bits);
232 
233 #ifndef PYTHON_PERF
234 	zstd_fini(&map->zstd_data);
235 #endif
236 
237 	perf_mmap__aio_munmap(map);
238 	if (map->data != NULL) {
239 		munmap(map->data, mmap__mmap_len(map));
240 		map->data = NULL;
241 	}
242 	auxtrace_mmap__munmap(&map->auxtrace_mmap);
243 }
244 
245 static void build_node_mask(int node, struct mmap_cpu_mask *mask)
246 {
247 	int idx, nr_cpus;
248 	struct perf_cpu cpu;
249 	const struct perf_cpu_map *cpu_map = NULL;
250 
251 	cpu_map = cpu_map__online();
252 	if (!cpu_map)
253 		return;
254 
255 	nr_cpus = perf_cpu_map__nr(cpu_map);
256 	for (idx = 0; idx < nr_cpus; idx++) {
257 		cpu = perf_cpu_map__cpu(cpu_map, idx); /* map c index to online cpu index */
258 		if (cpu__get_node(cpu) == node)
259 			__set_bit(cpu.cpu, mask->bits);
260 	}
261 }
262 
263 static int perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params *mp)
264 {
265 	map->affinity_mask.nbits = cpu__max_cpu().cpu;
266 	map->affinity_mask.bits = bitmap_zalloc(map->affinity_mask.nbits);
267 	if (!map->affinity_mask.bits)
268 		return -1;
269 
270 	if (mp->affinity == PERF_AFFINITY_NODE && cpu__max_node() > 1)
271 		build_node_mask(cpu__get_node(map->core.cpu), &map->affinity_mask);
272 	else if (mp->affinity == PERF_AFFINITY_CPU)
273 		__set_bit(map->core.cpu.cpu, map->affinity_mask.bits);
274 
275 	return 0;
276 }
277 
278 int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, struct perf_cpu cpu)
279 {
280 	if (perf_mmap__mmap(&map->core, &mp->core, fd, cpu)) {
281 		pr_debug2("failed to mmap perf event ring buffer, error %d\n",
282 			  errno);
283 		return -1;
284 	}
285 
286 	if (mp->affinity != PERF_AFFINITY_SYS &&
287 		perf_mmap__setup_affinity_mask(map, mp)) {
288 		pr_debug2("failed to alloc mmap affinity mask, error %d\n",
289 			  errno);
290 		return -1;
291 	}
292 
293 	if (verbose == 2)
294 		mmap_cpu_mask__scnprintf(&map->affinity_mask, "mmap");
295 
296 	map->core.flush = mp->flush;
297 
298 #ifndef PYTHON_PERF
299 	if (zstd_init(&map->zstd_data, mp->comp_level)) {
300 		pr_debug2("failed to init mmap compressor, error %d\n", errno);
301 		return -1;
302 	}
303 #endif
304 
305 	if (mp->comp_level && !perf_mmap__aio_enabled(map)) {
306 		map->data = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE,
307 				 MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
308 		if (map->data == MAP_FAILED) {
309 			pr_debug2("failed to mmap data buffer, error %d\n",
310 					errno);
311 			map->data = NULL;
312 			return -1;
313 		}
314 	}
315 
316 	if (auxtrace_mmap__mmap(&map->auxtrace_mmap,
317 				&mp->auxtrace_mp, map->core.base, fd))
318 		return -1;
319 
320 	return perf_mmap__aio_mmap(map, mp);
321 }
322 
323 int perf_mmap__push(struct mmap *md, void *to,
324 		    int push(struct mmap *map, void *to, void *buf, size_t size))
325 {
326 	u64 head = perf_mmap__read_head(&md->core);
327 	unsigned char *data = md->core.base + page_size;
328 	unsigned long size;
329 	void *buf;
330 	int rc = 0;
331 
332 	rc = perf_mmap__read_init(&md->core);
333 	if (rc < 0)
334 		return (rc == -EAGAIN) ? 1 : -1;
335 
336 	size = md->core.end - md->core.start;
337 
338 	if ((md->core.start & md->core.mask) + size != (md->core.end & md->core.mask)) {
339 		buf = &data[md->core.start & md->core.mask];
340 		size = md->core.mask + 1 - (md->core.start & md->core.mask);
341 		md->core.start += size;
342 
343 		if (push(md, to, buf, size) < 0) {
344 			rc = -1;
345 			goto out;
346 		}
347 	}
348 
349 	buf = &data[md->core.start & md->core.mask];
350 	size = md->core.end - md->core.start;
351 	md->core.start += size;
352 
353 	if (push(md, to, buf, size) < 0) {
354 		rc = -1;
355 		goto out;
356 	}
357 
358 	md->core.prev = head;
359 	perf_mmap__consume(&md->core);
360 out:
361 	return rc;
362 }
363 
364 int mmap_cpu_mask__duplicate(struct mmap_cpu_mask *original, struct mmap_cpu_mask *clone)
365 {
366 	clone->nbits = original->nbits;
367 	clone->bits  = bitmap_zalloc(original->nbits);
368 	if (!clone->bits)
369 		return -ENOMEM;
370 
371 	memcpy(clone->bits, original->bits, MMAP_CPU_MASK_BYTES(original));
372 	return 0;
373 }
374