linux/tools/perf/builtin-diff.c, branch v5.12

perf diff: Don't crash on freeing errno-session on the error path

2021-03-06T19:54:25Z

__cmd_diff() sets result of perf_session__new() to d->session. In case of failure, it's errno and perf-diff may crash with: failed to open perf.data: Permission denied Failed to open perf.data Segmentation fault (core dumped) From the coredump: 0 0x00005569a62b5955 in auxtrace__free (session=0xffffffffffffffff) at util/auxtrace.c:2681 1 0x00005569a626b37d in perf_session__delete (session=0xffffffffffffffff) at util/session.c:295 2 perf_session__delete (session=0xffffffffffffffff) at util/session.c:291 3 0x00005569a618008a in __cmd_diff () at builtin-diff.c:1239 4 cmd_diff (argc=, argv=) at builtin-diff.c:2011 [..] Funny enough, it won't always crash. For me it crashes only if failed file is second in cmd-line: the reason is that cmd_diff() check files for branch-stacks [in check_file_brstack()] and if the first file doesn't have brstacks, it doesn't proceed to try open other files from cmd-line. Check d->session before calling perf_session__delete(). Another solution would be assigning to temporary variable, checking it, but I find it easier to follow with IS_ERR() check in the same function. After some time it's still obvious why the check is needed, and with temp variable it's possible to make the same mistake. Committer testing: $ perf record sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.001 MB perf.data (8 samples) ] $ perf diff failed to open perf.data.old: No such file or directory Failed to open perf.data.old $ perf record sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.001 MB perf.data (8 samples) ] $ perf diff # Event 'cycles:u' # # Baseline Delta Abs Shared Object Symbol # ........ ......... ................ .......................... # 0.92% +87.66% [unknown] [k] 0xffffffff8825de16 11.39% +0.04% ld-2.32.so [.] __GI___tunables_init 87.70% ld-2.32.so [.] _dl_check_map_versions $ sudo chown root:root perf.data [sudo] password for acme: $ perf diff failed to open perf.data: Permission denied Failed to open perf.data Segmentation fault (core dumped) $ After the patch: $ perf diff failed to open perf.data: Permission denied Failed to open perf.data $ Signed-off-by: Dmitry Safonov Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Jiri Olsa Cc: Mark Rutland Cc: Peter Zijlstra Cc: dmitry safonov Link: http://lore.kernel.org/lkml/20210302023533.1572231-1-dima@arista.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Use the right prefix for 'struct evlist' diff methods

2020-11-30T18:18:48Z

perf_evlist__ is for 'struct perf_evlist' methods, in tools/lib/perf/, go on completing this split. Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Fix error return value in __cmd_diff()

2020-11-27T17:21:23Z

An appropriate return value should be set on the failed path. Fixes: 2a09a84c720b436a ("perf diff: Support hot streams comparison") Reported-by: Hulk Robot Signed-off-by: Zhen Lei Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Jin Yao Cc: Mark Rutland Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20201124103652.438-1-thunder.leizhen@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support hot streams comparison

2020-10-14T16:34:48Z

This patch enables perf-diff with "--stream" option. "--stream": Enable hot streams comparison Now let's see example. perf record -b ... Generate perf.data.old with branch data perf record -b ... Generate perf.data with branch data perf diff --stream [ Matched hot streams ] hot chain pair 1: cycles: 1, hits: 27.77% cycles: 1, hits: 9.24% --------------------------- -------------------------- main div.c:39 main div.c:39 main div.c:44 main div.c:44 hot chain pair 2: cycles: 34, hits: 20.06% cycles: 27, hits: 16.98% --------------------------- -------------------------- __random_r random_r.c:360 __random_r random_r.c:360 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:380 __random_r random_r.c:380 __random_r random_r.c:357 __random_r random_r.c:357 __random random.c:293 __random random.c:293 __random random.c:293 __random random.c:293 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:288 __random random.c:288 rand rand.c:27 rand rand.c:27 rand rand.c:26 rand rand.c:26 rand@plt rand@plt rand@plt rand@plt compute_flag div.c:25 compute_flag div.c:25 compute_flag div.c:22 compute_flag div.c:22 main div.c:40 main div.c:40 main div.c:40 main div.c:40 main div.c:39 main div.c:39 hot chain pair 3: cycles: 9, hits: 4.48% cycles: 6, hits: 4.51% --------------------------- -------------------------- __random_r random_r.c:360 __random_r random_r.c:360 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:380 __random_r random_r.c:380 [ Hot streams in old perf data only ] hot chain 1: cycles: 18, hits: 6.75% -------------------------- __random_r random_r.c:360 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:380 __random_r random_r.c:357 __random random.c:293 __random random.c:293 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:288 rand rand.c:27 rand rand.c:26 rand@plt rand@plt compute_flag div.c:25 compute_flag div.c:22 main div.c:40 hot chain 2: cycles: 29, hits: 2.78% -------------------------- compute_flag div.c:22 main div.c:40 main div.c:40 main div.c:39 [ Hot streams in new perf data only ] hot chain 1: cycles: 4, hits: 4.54% -------------------------- main div.c:42 compute_flag div.c:28 hot chain 2: cycles: 5, hits: 3.51% -------------------------- main div.c:39 main div.c:44 main div.c:42 compute_flag div.c:28 Signed-off-by: Jin Yao Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20201009022845.13141-8-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evsel__is_() to evsel__is()

2020-05-05T19:35:31Z

As those are 'struct evsel' methods, not part of tools/lib/perf/, aka libperf, to whom the perf_ prefix belongs. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evsel__set_sample_() to evsel__set_sample_()

2020-05-05T19:35:30Z

As they are not 'struct evsel' methods, not part of tools/lib/perf/, aka libperf, to whom the perf_ prefix belongs. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evselname() to evselname()

2020-05-05T19:35:30Z

As they are 'struct evsel' methods or related routines, not part of tools/lib/perf/, aka libperf, to whom the perf_ prefix belongs. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove unneeded semicolons

2020-04-30T13:48:32Z

Fixes coccicheck warnings: tools/perf/builtin-diff.c:1565:2-3: Unneeded semicolon tools/perf/builtin-lock.c:778:2-3: Unneeded semicolon tools/perf/builtin-mem.c:126:2-3: Unneeded semicolon tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c:555:2-3: Unneeded semicolon tools/perf/util/ordered-events.c:317:2-3: Unneeded semicolon tools/perf/util/synthetic-events.c:1131:2-3: Unneeded semicolon tools/perf/util/trace-event-read.c:78:2-3: Unneeded semicolon Reported-by: Hulk Robot Signed-off-by: Zou Wei Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/1588065523-71423-1-git-send-email-zou_wei@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Basic support for CGROUP event

2020-04-03T12:37:55Z

Implement basic functionality to support cgroup tracking. Each cgroup can be identified by inode number which can be read from userspace too. The actual cgroup processing will come in the later patch. Reported-by: kernel test robot Signed-off-by: Namhyung Kim Cc: Adrian Hunter [ fix perf test failure on sampling parsing ] Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20200325124536.2800725-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Use __block_info__cmp() to replace block_pair_cmp()

2020-03-10T00:43:25Z

'perf diff' uses block_pair_cmp() to compare two blocks. But block_info__cmp() has the similar functionality and it's a bit more complete. This patch removes block_pair_cmp() and uses __block_info__cmp() instead. __block_info__cmp() is wrapped by block_info__cmp() and it doesn't receives a perf_hpp_fmt parameter. Signed-off-by: Jin Yao Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jin Yao Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20200202141655.32053-3-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo