From cb9dd49e11f83d548c822d7022ac180b0518b25c Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 11 Jun 2012 19:03:32 -0300 Subject: [PATCH] perf tools: Fix synthesizing tracepoint names from the perf.data headers We need to use the per event info snapshoted at record time to synthesize the events name, so do it just after reading the perf.data headers, when we already processed the /sys events data, otherwise we'll end up using the local /sys that only by sheer luck will have the same tracepoint ID -> real event association. Example: # uname -a Linux felicio.ghostprotocols.net 3.4.0-rc5+ #1 SMP Sat May 19 15:27:11 BRT 2012 x86_64 x86_64 x86_64 GNU/Linux # perf record -e sched:sched_switch usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.015 MB perf.data (~648 samples) ] # cat /t/events/sched/sched_switch/id 279 # perf evlist -v sched:sched_switch: sample_freq=1, type: 2, config: 279, size: 80, sample_type: 1159, read_format: 7, disabled: 1, inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, sample_id_all: 1, exclude_guest: 1 # So on the above machine the sched:sched_switch has tracepoint id 279, but on the machine were we'll analyse it it has a different id: $ cat /t/events/sched/sched_switch/id 56 $ perf evlist -i /tmp/perf.data kmem:mm_balancedirty_writeout $ cat /t/events/kmem/mm_balancedirty_writeout/id 279 With this fix: $ perf evlist -i /tmp/perf.data sched:sched_switch Reported-by: Dmitry Antipov Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-auwks8fpuhmrdpiefs55o5oz@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 4f9b247fb312..e909d43cf542 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2093,6 +2093,35 @@ static int read_attr(int fd, struct perf_header *ph, return ret <= 0 ? -1 : 0; } +static int perf_evsel__set_tracepoint_name(struct perf_evsel *evsel) +{ + struct event_format *event = trace_find_event(evsel->attr.config); + char bf[128]; + + if (event == NULL) + return -1; + + snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name); + evsel->name = strdup(bf); + if (event->name == NULL) + return -1; + + return 0; +} + +static int perf_evlist__set_tracepoint_names(struct perf_evlist *evlist) +{ + struct perf_evsel *pos; + + list_for_each_entry(pos, &evlist->entries, node) { + if (pos->attr.type == PERF_TYPE_TRACEPOINT && + perf_evsel__set_tracepoint_name(pos)) + return -1; + } + + return 0; +} + int perf_session__read_header(struct perf_session *session, int fd) { struct perf_header *header = &session->header; @@ -2174,6 +2203,9 @@ int perf_session__read_header(struct perf_session *session, int fd) lseek(fd, header->data_offset, SEEK_SET); + if (perf_evlist__set_tracepoint_names(session->evlist)) + goto out_delete_evlist; + header->frozen = 1; return 0; out_errno: -- GitLab