diff options
Diffstat (limited to 'tools/perf/util/mmap.c')
-rw-r--r-- | tools/perf/util/mmap.c | 260 |
1 files changed, 15 insertions, 245 deletions
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index a35dc57d5995..063d1b93c53d 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -13,6 +13,7 @@ #include <stdlib.h> #include <string.h> #include <unistd.h> // sysconf() +#include <perf/mmap.h> #ifdef HAVE_LIBNUMA_SUPPORT #include <numaif.h> #endif @@ -23,116 +24,9 @@ #include "../perf.h" #include <internal/lib.h> /* page_size */ -size_t perf_mmap__mmap_len(struct mmap *map) +size_t mmap__mmap_len(struct mmap *map) { - return map->core.mask + 1 + page_size; -} - -/* When check_messup is true, 'end' must points to a good entry */ -static union perf_event *perf_mmap__read(struct mmap *map, - u64 *startp, u64 end) -{ - unsigned char *data = map->core.base + page_size; - union perf_event *event = NULL; - int diff = end - *startp; - - if (diff >= (int)sizeof(event->header)) { - size_t size; - - event = (union perf_event *)&data[*startp & map->core.mask]; - size = event->header.size; - - if (size < sizeof(event->header) || diff < (int)size) - return NULL; - - /* - * Event straddles the mmap boundary -- header should always - * be inside due to u64 alignment of output. - */ - if ((*startp & map->core.mask) + size != ((*startp + size) & map->core.mask)) { - unsigned int offset = *startp; - unsigned int len = min(sizeof(*event), size), cpy; - void *dst = map->core.event_copy; - - do { - cpy = min(map->core.mask + 1 - (offset & map->core.mask), len); - memcpy(dst, &data[offset & map->core.mask], cpy); - offset += cpy; - dst += cpy; - len -= cpy; - } while (len); - - event = (union perf_event *)map->core.event_copy; - } - - *startp += size; - } - - return event; -} - -/* - * Read event from ring buffer one by one. - * Return one event for each call. - * - * Usage: - * perf_mmap__read_init() - * while(event = perf_mmap__read_event()) { - * //process the event - * perf_mmap__consume() - * } - * perf_mmap__read_done() - */ -union perf_event *perf_mmap__read_event(struct mmap *map) -{ - union perf_event *event; - - /* - * Check if event was unmapped due to a POLLHUP/POLLERR. - */ - if (!refcount_read(&map->core.refcnt)) - return NULL; - - /* non-overwirte doesn't pause the ringbuffer */ - if (!map->core.overwrite) - map->core.end = perf_mmap__read_head(map); - - event = perf_mmap__read(map, &map->core.start, map->core.end); - - if (!map->core.overwrite) - map->core.prev = map->core.start; - - return event; -} - -static bool perf_mmap__empty(struct mmap *map) -{ - return perf_mmap__read_head(map) == map->core.prev && !map->auxtrace_mmap.base; -} - -void perf_mmap__get(struct mmap *map) -{ - refcount_inc(&map->core.refcnt); -} - -void perf_mmap__put(struct mmap *map) -{ - BUG_ON(map->core.base && refcount_read(&map->core.refcnt) == 0); - - if (refcount_dec_and_test(&map->core.refcnt)) - perf_mmap__munmap(map); -} - -void perf_mmap__consume(struct mmap *map) -{ - if (!map->core.overwrite) { - u64 old = map->core.prev; - - perf_mmap__write_tail(map, old); - } - - if (refcount_read(&map->core.refcnt) == 1 && perf_mmap__empty(map)) - perf_mmap__put(map); + return perf_mmap__mmap_len(&map->core); } int __weak auxtrace_mmap__mmap(struct auxtrace_mmap *mm __maybe_unused, @@ -170,7 +64,7 @@ static int perf_mmap__aio_enabled(struct mmap *map) #ifdef HAVE_LIBNUMA_SUPPORT static int perf_mmap__aio_alloc(struct mmap *map, int idx) { - map->aio.data[idx] = mmap(NULL, perf_mmap__mmap_len(map), PROT_READ|PROT_WRITE, + map->aio.data[idx] = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0); if (map->aio.data[idx] == MAP_FAILED) { map->aio.data[idx] = NULL; @@ -183,7 +77,7 @@ static int perf_mmap__aio_alloc(struct mmap *map, int idx) static void perf_mmap__aio_free(struct mmap *map, int idx) { if (map->aio.data[idx]) { - munmap(map->aio.data[idx], perf_mmap__mmap_len(map)); + munmap(map->aio.data[idx], mmap__mmap_len(map)); map->aio.data[idx] = NULL; } } @@ -196,7 +90,7 @@ static int perf_mmap__aio_bind(struct mmap *map, int idx, int cpu, int affinity) if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) { data = map->aio.data[idx]; - mmap_len = perf_mmap__mmap_len(map); + mmap_len = mmap__mmap_len(map); node_mask = 1UL << cpu__get_node(cpu); if (mbind(data, mmap_len, MPOL_BIND, &node_mask, 1, 0)) { pr_err("Failed to bind [%p-%p] AIO buffer to node %d: error %m\n", @@ -210,7 +104,7 @@ static int perf_mmap__aio_bind(struct mmap *map, int idx, int cpu, int affinity) #else /* !HAVE_LIBNUMA_SUPPORT */ static int perf_mmap__aio_alloc(struct mmap *map, int idx) { - map->aio.data[idx] = malloc(perf_mmap__mmap_len(map)); + map->aio.data[idx] = malloc(mmap__mmap_len(map)); if (map->aio.data[idx] == NULL) return -1; @@ -311,19 +205,13 @@ static void perf_mmap__aio_munmap(struct mmap *map __maybe_unused) } #endif -void perf_mmap__munmap(struct mmap *map) +void mmap__munmap(struct mmap *map) { perf_mmap__aio_munmap(map); if (map->data != NULL) { - munmap(map->data, perf_mmap__mmap_len(map)); + munmap(map->data, mmap__mmap_len(map)); map->data = NULL; } - if (map->core.base != NULL) { - munmap(map->core.base, perf_mmap__mmap_len(map)); - map->core.base = NULL; - map->core.fd = -1; - refcount_set(&map->core.refcnt, 0); - } auxtrace_mmap__munmap(&map->auxtrace_mmap); } @@ -353,34 +241,13 @@ static void perf_mmap__setup_affinity_mask(struct mmap *map, struct mmap_params CPU_SET(map->core.cpu, &map->affinity_mask); } -int perf_mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu) +int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu) { - /* - * The last one will be done at perf_mmap__consume(), so that we - * make sure we don't prevent tools from consuming every last event in - * the ring buffer. - * - * I.e. we can get the POLLHUP meaning that the fd doesn't exist - * anymore, but the last events for it are still in the ring buffer, - * waiting to be consumed. - * - * Tools can chose to ignore this at their own discretion, but the - * evlist layer can't just drop it when filtering events in - * perf_evlist__filter_pollfd(). - */ - refcount_set(&map->core.refcnt, 2); - map->core.prev = 0; - map->core.mask = mp->mask; - map->core.base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot, - MAP_SHARED, fd, 0); - if (map->core.base == MAP_FAILED) { + if (perf_mmap__mmap(&map->core, &mp->core, fd, cpu)) { pr_debug2("failed to mmap perf event ring buffer, error %d\n", errno); - map->core.base = NULL; return -1; } - map->core.fd = fd; - map->core.cpu = cpu; perf_mmap__setup_affinity_mask(map, mp); @@ -389,7 +256,7 @@ int perf_mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu) map->comp_level = mp->comp_level; if (map->comp_level && !perf_mmap__aio_enabled(map)) { - map->data = mmap(NULL, perf_mmap__mmap_len(map), PROT_READ|PROT_WRITE, + map->data = mmap(NULL, mmap__mmap_len(map), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0); if (map->data == MAP_FAILED) { pr_debug2("failed to mmap data buffer, error %d\n", @@ -406,96 +273,16 @@ int perf_mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu) return perf_mmap__aio_mmap(map, mp); } -static int overwrite_rb_find_range(void *buf, int mask, u64 *start, u64 *end) -{ - struct perf_event_header *pheader; - u64 evt_head = *start; - int size = mask + 1; - - pr_debug2("%s: buf=%p, start=%"PRIx64"\n", __func__, buf, *start); - pheader = (struct perf_event_header *)(buf + (*start & mask)); - while (true) { - if (evt_head - *start >= (unsigned int)size) { - pr_debug("Finished reading overwrite ring buffer: rewind\n"); - if (evt_head - *start > (unsigned int)size) - evt_head -= pheader->size; - *end = evt_head; - return 0; - } - - pheader = (struct perf_event_header *)(buf + (evt_head & mask)); - - if (pheader->size == 0) { - pr_debug("Finished reading overwrite ring buffer: get start\n"); - *end = evt_head; - return 0; - } - - evt_head += pheader->size; - pr_debug3("move evt_head: %"PRIx64"\n", evt_head); - } - WARN_ONCE(1, "Shouldn't get here\n"); - return -1; -} - -/* - * Report the start and end of the available data in ringbuffer - */ -static int __perf_mmap__read_init(struct mmap *md) -{ - u64 head = perf_mmap__read_head(md); - u64 old = md->core.prev; - unsigned char *data = md->core.base + page_size; - unsigned long size; - - md->core.start = md->core.overwrite ? head : old; - md->core.end = md->core.overwrite ? old : head; - - if ((md->core.end - md->core.start) < md->core.flush) - return -EAGAIN; - - size = md->core.end - md->core.start; - if (size > (unsigned long)(md->core.mask) + 1) { - if (!md->core.overwrite) { - WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n"); - - md->core.prev = head; - perf_mmap__consume(md); - return -EAGAIN; - } - - /* - * Backward ring buffer is full. We still have a chance to read - * most of data from it. - */ - if (overwrite_rb_find_range(data, md->core.mask, &md->core.start, &md->core.end)) - return -EINVAL; - } - - return 0; -} - -int perf_mmap__read_init(struct mmap *map) -{ - /* - * Check if event was unmapped due to a POLLHUP/POLLERR. - */ - if (!refcount_read(&map->core.refcnt)) - return -ENOENT; - - return __perf_mmap__read_init(map); -} - int perf_mmap__push(struct mmap *md, void *to, int push(struct mmap *map, void *to, void *buf, size_t size)) { - u64 head = perf_mmap__read_head(md); + u64 head = perf_mmap__read_head(&md->core); unsigned char *data = md->core.base + page_size; unsigned long size; void *buf; int rc = 0; - rc = perf_mmap__read_init(md); + rc = perf_mmap__read_init(&md->core); if (rc < 0) return (rc == -EAGAIN) ? 1 : -1; @@ -522,24 +309,7 @@ int perf_mmap__push(struct mmap *md, void *to, } md->core.prev = head; - perf_mmap__consume(md); + perf_mmap__consume(&md->core); out: return rc; } - -/* - * Mandatory for overwrite mode - * The direction of overwrite mode is backward. - * The last perf_mmap__read() will set tail to map->core.prev. - * Need to correct the map->core.prev to head which is the end of next read. - */ -void perf_mmap__read_done(struct mmap *map) -{ - /* - * Check if event was unmapped due to a POLLHUP/POLLERR. - */ - if (!refcount_read(&map->core.refcnt)) - return; - - map->core.prev = perf_mmap__read_head(map); -} |