From baa2f6cedbfae962f04281a31f08ec29667d31a0 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 26 Nov 2010 19:39:15 -0200 Subject: [PATCH] perf record: Add option to disable collecting build-ids Collecting build-ids for long running sessions may take a long time because it needs to traverse the whole just collected perf.data stream of events, marking the DSOs that had hits and then looking for the .note.gnu.build-id ELF section. For things like the 'trace' tool that records and right away consumes the data on systems where its unlikely that the DSOs being monitored will change while 'trace' runs, it is desirable to remove build id collection, so add a -B/--no-buildid option to perf record to allow such use case. Longer term we'll avoid all this if we, at DSO load time, in the kernel, take advantage of this slow code path to collect the build-id and stash it somewhere, so that we can insert it in the PERF_RECORD_MMAP event. Reported-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Tom Zanussi LKML-Reference: Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 14 +++++++++++--- tools/perf/util/header.c | 11 +++++++++-- tools/perf/util/header.h | 1 + tools/perf/util/include/linux/bitops.h | 5 +++++ 4 files changed, 26 insertions(+), 5 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 3d2cb4899807..024e1441d76b 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -61,6 +61,7 @@ static bool inherit_stat = false; static bool no_samples = false; static bool sample_address = false; static bool no_buildid = false; +static bool no_buildid_cache = false; static long samples = 0; static u64 bytes_written = 0; @@ -437,7 +438,8 @@ static void atexit_header(void) if (!pipe_output) { session->header.data_size += bytes_written; - process_buildids(); + if (!no_buildid) + process_buildids(); perf_header__write(&session->header, output, true); perf_session__delete(session); symbol__exit(); @@ -557,6 +559,9 @@ static int __cmd_record(int argc, const char **argv) return -1; } + if (!no_buildid) + perf_header__set_feat(&session->header, HEADER_BUILD_ID); + if (!file_new) { err = perf_header__read(session, output); if (err < 0) @@ -831,8 +836,10 @@ const struct option record_options[] = { "Sample addresses"), OPT_BOOLEAN('n', "no-samples", &no_samples, "don't sample"), - OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid, + OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid_cache, "do not update the buildid cache"), + OPT_BOOLEAN('B', "no-buildid", &no_buildid, + "do not collect buildids in perf.data"), OPT_END() }; @@ -857,7 +864,8 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) } symbol__init(); - if (no_buildid) + + if (no_buildid_cache || no_buildid) disable_buildid_cache(); if (!nr_counters) { diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index d7e67b167ea3..f65d7dc127b6 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -152,6 +152,11 @@ void perf_header__set_feat(struct perf_header *self, int feat) set_bit(feat, self->adds_features); } +void perf_header__clear_feat(struct perf_header *self, int feat) +{ + clear_bit(feat, self->adds_features); +} + bool perf_header__has_feat(const struct perf_header *self, int feat) { return test_bit(feat, self->adds_features); @@ -431,8 +436,10 @@ static int perf_header__adds_write(struct perf_header *self, int fd) int idx = 0, err; session = container_of(self, struct perf_session, header); - if (perf_session__read_build_ids(session, true)) - perf_header__set_feat(self, HEADER_BUILD_ID); + + if (perf_header__has_feat(self, HEADER_BUILD_ID && + !perf_session__read_build_ids(session, true))) + perf_header__clear_feat(self, HEADER_BUILD_ID); nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS); if (!nr_sections) diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index 402ac2454cf8..ed550bffd655 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -84,6 +84,7 @@ u64 perf_header__sample_type(struct perf_header *header); struct perf_event_attr * perf_header__find_attr(u64 id, struct perf_header *header); void perf_header__set_feat(struct perf_header *self, int feat); +void perf_header__clear_feat(struct perf_header *self, int feat); bool perf_header__has_feat(const struct perf_header *self, int feat); int perf_header__process_sections(struct perf_header *self, int fd, diff --git a/tools/perf/util/include/linux/bitops.h b/tools/perf/util/include/linux/bitops.h index bb4ac2e05385..8be0b968ca0b 100644 --- a/tools/perf/util/include/linux/bitops.h +++ b/tools/perf/util/include/linux/bitops.h @@ -13,6 +13,11 @@ static inline void set_bit(int nr, unsigned long *addr) addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG); } +static inline void clear_bit(int nr, unsigned long *addr) +{ + addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG)); +} + static __always_inline int test_bit(unsigned int nr, const unsigned long *addr) { return ((1UL << (nr % BITS_PER_LONG)) & -- GitLab