kernel.git/tools/perf/builtin-stat.c, branch linux-4.4.y

perf stat: Fix a segmentation fault when using repeat forever

2019-10-17T20:40:56Z

[ Upstream commit 443f2d5ba13d65ccfd879460f77941875159d154 ] Observe a segmentation fault when 'perf stat' is asked to repeat forever with the interval option. Without fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.000211692 3,13,89,82,34,157 cycles 10.000380119 1,53,98,52,22,294 cycles 10.040467280 17,16,79,265 cycles Segmentation fault This problem was only observed when we use forever option aka -r 0 and works with limited repeats. Calling print_counter with ts being set to NULL, is not a correct option when interval is set. Hence avoid print_counter(NULL,..) if interval is set. With fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.019866622 3,15,14,43,08,697 cycles 10.039865756 3,15,16,31,95,261 cycles 10.059950628 1,26,05,47,158 cycles 5.009902655 3,14,52,62,33,932 cycles 10.019880228 3,14,52,22,89,154 cycles 10.030543876 66,90,18,333 cycles 5.009848281 3,14,51,98,25,437 cycles 10.029854402 3,15,14,93,04,918 cycles 5.009834177 3,14,51,95,92,316 cycles Committer notes: Did the 'git bisect' to find the cset introducing the problem to add the Fixes tag below, and at that time the problem reproduced as: (gdb) run stat -r0 -I500 sleep 1 Program received signal SIGSEGV, Segmentation fault. print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 866 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep); (gdb) bt #0 print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 #1 0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938 #2 0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=) at builtin-stat.c:1411 #3 0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 , argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370 #4 0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429 #5 0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473 #6 0x000000000045cac9 in main (argc=, argv=) at perf.c:588 (gdb) Mostly the same as just before this patch: Program received signal SIGSEGV, Segmentation fault. 0x00000000005874a7 in print_interval (config=0xa1f2a0 , evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 964 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep); (gdb) bt #0 0x00000000005874a7 in print_interval (config=0xa1f2a0 , evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 #1 0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 , _target=0xa1f0c0 , ts=0x0, argc=2, argv=0x7fffffffd670) at util/stat-display.c:1172 #2 0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656 #3 0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960 #4 0x00000000004dd2e0 in run_builtin (p=0xa30e00 , argc=5, argv=0x7fffffffd670) at perf.c:310 #5 0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362 #6 0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406 #7 0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531 (gdb) Fixes: d4f63a4741a8 ("perf stat: Introduce print_counters function") Signed-off-by: Srikar Dronamraju Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Tested-by: Ravi Bangoria Cc: Namhyung Kim Cc: Naveen N. Rao Cc: stable@vger.kernel.org # v4.2+ Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf stat: Make stat options global

2015-11-05T20:54:34Z

So they can be used in perf stat record command in following patch. Signed-off-by: Jiri Olsa Tested-by: Kan Liang Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1446734469-11352-2-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Use common printout function to avoid duplicated code

2015-11-04T18:12:04Z

Instead of every caller deciding whether to call abs or nsec printout do it all in a single central function. No functional changes. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/1446515428-7450-3-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Move sw clock metrics printout to stat-shadow

2015-11-04T18:11:41Z

The sw clock metrics printing was missed in the earlier move to stat-shadow of all the other metric printouts. Move it too. v2: Fix metrics printing in this version to make bisect safe. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/1446515428-7450-2-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Cache aggregated map entries in extra cpumap

2015-10-27T18:08:07Z

Currently any time we need to access socket or core id for given cpu, we access the sysfs topology file. Adding a cpus_aggr_map cpu_map to cache those entries. Signed-off-by: Jiri Olsa Tested-by: Kan Liang Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1445784728-21732-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf cpu_map: Add data arg to cpu_map__build_map callback

2015-10-19T21:04:01Z

Adding data arg to cpu_map__build_map callback, so we could pass data along to the callback. It'll be needed in following patches to retrieve topology info from perf.data. Signed-off-by: Jiri Olsa Tested-by: Kan Liang Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1444992092-17897-41-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Add AGGR_UNSET mode

2015-10-19T21:02:07Z

Adding AGGR_UNSET mode, so we could distinguish unset aggr_mode in following patches. Signed-off-by: Jiri Olsa Tested-by: Kan Liang Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1444992092-17897-30-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Rename perf_stat struct into perf_stat_evsel

2015-10-19T21:01:05Z

It's used as the perf_evsel::priv data, so the name suits better. Also we'll need the perf_stat name free for more generic struct. Signed-off-by: Jiri Olsa Tested-by: Kan Liang Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1444992092-17897-29-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Reduce min --interval-print to 10ms

2015-10-02T20:07:55Z

The --interval-print parameter was limited to 100ms. However, for example, 10ms is required to do sophisticated bandwidth analysis using uncore events. The test shows that the overhead of the system-wide uncore monitoring with 10ms interval is only ~2%. So this patch reduces the minimal interval-print allowd to 10ms. But 10ms may not work well for all cases. For example, when the cpus/threads number is very large, for system-wide core event monitoring the overhead could be high. To handle this issue, a warning will be displayed when the interval-print is set between 10ms to 100ms. So users can make a decision according to their specific cases. # perf stat -e uncore_imc_1/cas_count_read/ -a --interval-print 10 -- sleep 1 print interval < 100ms. The overhead percentage could be high in some cases. Please proceed with caution. # time counts unit events 0.010200451 0.10 MiB uncore_imc_1/cas_count_read/ 0.020475117 0.02 MiB uncore_imc_1/cas_count_read/ 0.030692800 0.01 MiB uncore_imc_1/cas_count_read/ 0.040948161 0.02 MiB uncore_imc_1/cas_count_read/ 0.051159564 0.00 MiB uncore_imc_1/cas_count_read/ Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Link: http://lkml.kernel.org/r/1443776674-42511-1-git-send-email-kan.liang@intel.com [ Added warning about overhead when using sub 100ms intervals to the man page ] Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Quieten failed to read counter message

2015-09-02T19:30:47Z

Since 3b3eb0445 running perf stat on a system without backend-stalled-cycles spits out ugly warnings by default. Since that is quite common, make the message a debug message only. We know anyways that the counter wasn't read by the normal output. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/1441147966-14917-1-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo