From d4c6fb36ac2c82f8f0c05b04cf102dcdc2d5a14d Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Fri, 20 May 2016 16:38:24 +0000 Subject: perf evsel: Record fd into perf_mmap Add a fd field into struct perf_mmap so that perf can track the mmap fd. This feature will be used for toggling overwrite ring buffers. Signed-off-by: Wang Nan Cc: He Kuang Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463762315-155689-3-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.h | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/perf/util/evlist.h') diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 85d1b59802e8..0d165b1d8f77 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -28,6 +28,7 @@ struct record_opts; struct perf_mmap { void *base; int mask; + int fd; atomic_t refcnt; u64 prev; struct auxtrace_mmap auxtrace_mmap; -- cgit v1.2.3-70-g09d2 From 65aea2338765da1a58cc26eeb84d72308492ecb5 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Mon, 23 May 2016 07:13:38 +0000 Subject: perf evlist: Add API to pause/resume perf_evlist__toggle_{pause,resume}() are introduced to pause/resume events in an evlist. Utilize PERF_EVENT_IOC_PAUSE_OUTPUT ioctl. Following commits use them to ensure overwrite ring buffer is paused before reading. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463987628-163563-2-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang [ Return -1, like all other ioctl() usage in evlist.c, rename 'pause' arg to avoid breaking the build on ubuntu 12.04 and other old systems ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 27 +++++++++++++++++++++++++++ tools/perf/util/evlist.h | 2 ++ 2 files changed, 29 insertions(+) (limited to 'tools/perf/util/evlist.h') diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 1a370db02a8c..904523a2be90 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -679,6 +679,33 @@ static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist, return NULL; } +static int perf_evlist__set_paused(struct perf_evlist *evlist, bool value) +{ + int i; + + for (i = 0; i < evlist->nr_mmaps; i++) { + int fd = evlist->mmap[i].fd; + int err; + + if (fd < 0) + continue; + err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0); + if (err) + return err; + } + return 0; +} + +int perf_evlist__pause(struct perf_evlist *evlist) +{ + return perf_evlist__set_paused(evlist, true); +} + +int perf_evlist__resume(struct perf_evlist *evlist) +{ + return perf_evlist__set_paused(evlist, false); +} + /* When check_messup is true, 'end' must points to a good entry */ static union perf_event * perf_mmap__read(struct perf_mmap *md, bool check_messup, u64 start, diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 0d165b1d8f77..97090b70976d 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -136,6 +136,8 @@ void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx); void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx); +int perf_evlist__pause(struct perf_evlist *evlist); +int perf_evlist__resume(struct perf_evlist *evlist); int perf_evlist__open(struct perf_evlist *evlist); void perf_evlist__close(struct perf_evlist *evlist); -- cgit v1.2.3-70-g09d2 From 3a62a7b8200a177ad96161e4f2678514e6ee301e Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Mon, 23 May 2016 07:13:41 +0000 Subject: perf record: Read from backward ring buffer Introduce rb_find_range() to find start and end position from a backward ring buffer. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463987628-163563-5-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/evlist.c | 1 + tools/perf/util/evlist.h | 1 + 3 files changed, 54 insertions(+) (limited to 'tools/perf/util/evlist.h') diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 73ce651c84f6..dc3fcb597e4c 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -83,6 +83,54 @@ static int process_synthesized_event(struct perf_tool *tool, return record__write(rec, event, event->header.size); } +static int +backward_rb_find_range(void *buf, int mask, u64 head, u64 *start, u64 *end) +{ + struct perf_event_header *pheader; + u64 evt_head = head; + int size = mask + 1; + + pr_debug2("backward_rb_find_range: buf=%p, head=%"PRIx64"\n", buf, head); + pheader = (struct perf_event_header *)(buf + (head & mask)); + *start = head; + while (true) { + if (evt_head - head >= (unsigned int)size) { + pr_debug("Finshed reading backward ring buffer: rewind\n"); + if (evt_head - head > (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("Finshed reading backward 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; +} + +static int +rb_find_range(struct perf_evlist *evlist, + void *data, int mask, u64 head, u64 old, + u64 *start, u64 *end) +{ + if (!evlist->backward) { + *start = old; + *end = head; + return 0; + } + + return backward_rb_find_range(data, mask, head, start, end); +} + static int record__mmap_read(struct record *rec, int idx) { struct perf_mmap *md = &rec->evlist->mmap[idx]; @@ -94,6 +142,10 @@ static int record__mmap_read(struct record *rec, int idx) void *buf; int rc = 0; + if (rb_find_range(rec->evlist, data, md->mask, head, + old, &start, &end)) + return -1; + if (start == end) return 0; diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 904523a2be90..e82ba90cc969 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -44,6 +44,7 @@ void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus, perf_evlist__set_maps(evlist, cpus, threads); fdarray__init(&evlist->pollfd, 64); evlist->workload.pid = -1; + evlist->backward = false; } struct perf_evlist *perf_evlist__new(void) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 97090b70976d..d740fb877ab6 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -44,6 +44,7 @@ struct perf_evlist { bool overwrite; bool enabled; bool has_user_cpus; + bool backward; size_t mmap_len; int id_pos; int is_pos; -- cgit v1.2.3-70-g09d2