xref: /openbmc/linux/tools/perf/util/mmap.c (revision 78560d41)
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 					  int idx __maybe_unused,
66 					  bool per_cpu __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, int cpu, int affinity)
98 {
99 	void *data;
100 	size_t mmap_len;
101 	unsigned long node_mask;
102 
103 	if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) {
104 		data = map->aio.data[idx];
105 		mmap_len = mmap__mmap_len(map);
106 		node_mask = 1UL << cpu__get_node(cpu);
107 		if (mbind(data, mmap_len, MPOL_BIND, &node_mask, 1, 0)) {
108 			pr_err("Failed to bind [%p-%p] AIO buffer to node %d: error %m\n",
109 				data, data + mmap_len, cpu__get_node(cpu));
110 			return -1;
111 		}
112 	}
113 
114 	return 0;
115 }
116 #else /* !HAVE_LIBNUMA_SUPPORT */
117 static int perf_mmap__aio_alloc(struct mmap *map, int idx)
118 {
119 	map->aio.data[idx] = malloc(mmap__mmap_len(map));
120 	if (map->aio.data[idx] == NULL)
121 		return -1;
122 
123 	return 0;
124 }
125 
126 static void perf_mmap__aio_free(struct mmap *map, int idx)
127 {
128 	zfree(&(map->aio.data[idx]));
129 }
130 
131 static int perf_mmap__aio_bind(struct mmap *map __maybe_unused, int idx __maybe_unused,
132 		int cpu __maybe_unused, int affinity __maybe_unused)
133 {
134 	return 0;
135 }
136 #endif
137 
138 static int perf_mmap__aio_mmap(struct mmap *map, struct mmap_params *mp)
139 {
140 	int delta_max, i, prio, ret;
141 
142 	map->aio.nr_cblocks = mp->nr_cblocks;
143 	if (map->aio.nr_cblocks) {
144 		map->aio.aiocb = calloc(map->aio.nr_cblocks, sizeof(struct aiocb *));
145 		if (!map->aio.aiocb) {
146 			pr_debug2("failed to allocate aiocb for data buffer, error %m\n");
147 			return -1;
148 		}
149 		map->aio.cblocks = calloc(map->aio.nr_cblocks, sizeof(struct aiocb));
150 		if (!map->aio.cblocks) {
151 			pr_debug2("failed to allocate cblocks for data buffer, error %m\n");
152 			return -1;
153 		}
154 		map->aio.data = calloc(map->aio.nr_cblocks, sizeof(void *));
155 		if (!map->aio.data) {
156 			pr_debug2("failed to allocate data buffer, error %m\n");
157 			return -1;
158 		}
159 		delta_max = sysconf(_SC_AIO_PRIO_DELTA_MAX);
160 		for (i = 0; i < map->aio.nr_cblocks; ++i) {
161 			ret = perf_mmap__aio_alloc(map, i);
162 			if (ret == -1) {
163 				pr_debug2("failed to allocate data buffer area, error %m");
164 				return -1;
165 			}
166 			ret = perf_mmap__aio_bind(map, i, map->core.cpu, mp->affinity);
167 			if (ret == -1)
168 				return -1;
169 			/*
170 			 * Use cblock.aio_fildes value different from -1
171 			 * to denote started aio write operation on the
172 			 * cblock so it requires explicit record__aio_sync()
173 			 * call prior the cblock may be reused again.
174 			 */
175 			map->aio.cblocks[i].aio_fildes = -1;
176 			/*
177 			 * Allocate cblocks with priority delta to have
178 			 * faster aio write system calls because queued requests
179 			 * are kept in separate per-prio queues and adding
180 			 * a new request will iterate thru shorter per-prio
181 			 * list. Blocks with numbers higher than
182 			 *  _SC_AIO_PRIO_DELTA_MAX go with priority 0.
183 			 */
184 			prio = delta_max - i;
185 			map->aio.cblocks[i].aio_reqprio = prio >= 0 ? prio : 0;
186 		}
187 	}
188 
189 	return 0;
190 }
191 
192 static void perf_mmap__aio_munmap(struct mmap *map)
193 {
194 	int i;
195 
196 	for (i = 0; i < map->aio.nr_cblocks; ++i)
197 		perf_mmap__aio_free(map, i);
198 	if (map->aio.data)
199 		zfree(&map->aio.data);
200 	zfree(&map->aio.cblocks);
201 	zfree(&map->aio.aiocb);
202 }
203 #else /* !HAVE_AIO_SUPPORT */
204 static int perf_mmap__aio_enabled(struct mmap *map __maybe_unused)
205 {
206 	return 0;
207 }
208 
209 static int perf_mmap__aio_mmap(struct mmap *map __maybe_unused,
210 			       struct mmap_params *mp __maybe_unused)
211 {
212 	return 0;
213 }
214 
215 static void perf_mmap__aio_munmap(struct mmap *map __maybe_unused)
216 {
217 }
218 #endif
219 
220 void mmap__munmap(struct mmap *map)
221 {
222 	bitmap_free(map->affinity_mask.bits);
223 
224 	perf_mmap__aio_munmap(map);
225 	if (map->data != NULL) {
226 		munmap(map->data, mmap__mmap_len(map));
227 		map->data = NULL;
228 	}
229 	auxtrace_mmap__munmap(&map->auxtrace_mmap);
230 }
231 
232 static void build_node_mask(int node, struct mmap_cpu_mask *mask)
233 {
234 	int c, cpu, nr_cpus;
235 	const struct perf_cpu_map *cpu_map = NULL;
236 
237 	cpu_map = cpu_map__online();
238 	if (!cpu_map)
239 		return;
240 
241 	nr_cpus = perf_cpu_map__nr(cpu_map);
242 	for (c = 0; c < nr_cpus; c++) {
243 		cpu = cpu_map->map[c]; /* map c index to online cpu index */
244 		if (cpu__get_node(cpu) == node)
245 			set_bit(cpu, mask->bits);
246 	}
247 }
248 
249 static int perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params *mp)
250 {
251 	map->affinity_mask.nbits = cpu__max_cpu();
252 	map->affinity_mask.bits = bitmap_alloc(map->affinity_mask.nbits);
253 	if (!map->affinity_mask.bits)
254 		return -1;
255 
256 	if (mp->affinity == PERF_AFFINITY_NODE && cpu__max_node() > 1)
257 		build_node_mask(cpu__get_node(map->core.cpu), &map->affinity_mask);
258 	else if (mp->affinity == PERF_AFFINITY_CPU)
259 		set_bit(map->core.cpu, map->affinity_mask.bits);
260 
261 	return 0;
262 }
263 
264 int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu)
265 {
266 	if (perf_mmap__mmap(&map->core, &mp->core, fd, cpu)) {
267 		pr_debug2("failed to mmap perf event ring buffer, error %d\n",
268 			  errno);
269 		return -1;
270 	}
271 
272 	if (mp->affinity != PERF_AFFINITY_SYS &&
273 		perf_mmap__setup_affinity_mask(map, mp)) {
274 		pr_debug2("failed to alloc mmap affinity mask, error %d\n",
275 			  errno);
276 		return -1;
277 	}
278 
279 	if (verbose == 2)
280 		mmap_cpu_mask__scnprintf(&map->affinity_mask, "mmap");
281 
282 	map->core.flush = mp->flush;
283 
284 	map->comp_level = mp->comp_level;
285 
286 	if (map->comp_level && !perf_mmap__aio_enabled(map)) {
287 		map->data = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE,
288 				 MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
289 		if (map->data == MAP_FAILED) {
290 			pr_debug2("failed to mmap data buffer, error %d\n",
291 					errno);
292 			map->data = NULL;
293 			return -1;
294 		}
295 	}
296 
297 	if (auxtrace_mmap__mmap(&map->auxtrace_mmap,
298 				&mp->auxtrace_mp, map->core.base, fd))
299 		return -1;
300 
301 	return perf_mmap__aio_mmap(map, mp);
302 }
303 
304 int perf_mmap__push(struct mmap *md, void *to,
305 		    int push(struct mmap *map, void *to, void *buf, size_t size))
306 {
307 	u64 head = perf_mmap__read_head(&md->core);
308 	unsigned char *data = md->core.base + page_size;
309 	unsigned long size;
310 	void *buf;
311 	int rc = 0;
312 
313 	rc = perf_mmap__read_init(&md->core);
314 	if (rc < 0)
315 		return (rc == -EAGAIN) ? 1 : -1;
316 
317 	size = md->core.end - md->core.start;
318 
319 	if ((md->core.start & md->core.mask) + size != (md->core.end & md->core.mask)) {
320 		buf = &data[md->core.start & md->core.mask];
321 		size = md->core.mask + 1 - (md->core.start & md->core.mask);
322 		md->core.start += size;
323 
324 		if (push(md, to, buf, size) < 0) {
325 			rc = -1;
326 			goto out;
327 		}
328 	}
329 
330 	buf = &data[md->core.start & md->core.mask];
331 	size = md->core.end - md->core.start;
332 	md->core.start += size;
333 
334 	if (push(md, to, buf, size) < 0) {
335 		rc = -1;
336 		goto out;
337 	}
338 
339 	md->core.prev = head;
340 	perf_mmap__consume(&md->core);
341 out:
342 	return rc;
343 }
344