kernel/tools/perf/builtin-stat.c, branch linux-4.17.y

perf stat: Fix duplicate PMU name for interval print

2018-04-24T19:12:00Z

PMU name is printed repeatedly for interval print, for example: perf stat --no-merge -e 'unc_m_clockticks' -a -I 1000 # time counts unit events 1.001053069 243,702,144 unc_m_clockticks [uncore_imc_4] 1.001053069 244,268,304 unc_m_clockticks [uncore_imc_2] 1.001053069 244,427,386 unc_m_clockticks [uncore_imc_0] 1.001053069 244,583,760 unc_m_clockticks [uncore_imc_5] 1.001053069 244,738,971 unc_m_clockticks [uncore_imc_3] 1.001053069 244,880,309 unc_m_clockticks [uncore_imc_1] 2.002024821 240,818,200 unc_m_clockticks [uncore_imc_4] [uncore_imc_4] 2.002024821 240,767,812 unc_m_clockticks [uncore_imc_2] [uncore_imc_2] 2.002024821 240,764,215 unc_m_clockticks [uncore_imc_0] [uncore_imc_0] 2.002024821 240,759,504 unc_m_clockticks [uncore_imc_5] [uncore_imc_5] 2.002024821 240,755,992 unc_m_clockticks [uncore_imc_3] [uncore_imc_3] 2.002024821 240,750,403 unc_m_clockticks [uncore_imc_1] [uncore_imc_1] For each print, the PMU name is unconditionally appended to the counter->name. Need to check the counter->name first. If the PMU name is already appended, do nothing. Committer notes: Add and use perf_evsel->uniquified_name bool instead of doing the more expensive strstr(event->name, pmu->name). Signed-off-by: Kan Liang Tested-by: Arnaldo Carvalho de Melo Cc: Agustin Vega-Frias Cc: Andi Kleen Cc: Ganapatrao Kulkarni Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Shaokun Zhang Cc: Will Deacon Fixes: 8c5421c016a4 ("perf pmu: Display pmu name when printing unmerged events in stat") Link: http://lkml.kernel.org/r/1524594014-79243-5-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Print out hint for mixed PMU group error

2018-04-24T19:11:59Z

Perf doesn't support mixed events from different PMUs (except software event) in a group. For this case, only "" or "" are printed out. There is no hint which guides users to fix the issue. Checking the PMU type of events to determine if they are from the same PMU. There may be false alarm for the checking. E.g. the core PMU has different PMU type. But it should not happen often. The false alarm can also be tolerated, because: - It only happens on error path. - It just provides a possible solution for the issue. Signed-off-by: Kan Liang Cc: Agustin Vega-Frias Cc: Andi Kleen Cc: Ganapatrao Kulkarni Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Shaokun Zhang Cc: Will Deacon Link: http://lkml.kernel.org/r/1524594014-79243-2-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Enable 1ms interval for printing event counters values

2018-04-12T12:29:31Z

Currently print count interval for performance counters values is limited by 10ms so reading the values at frequencies higher than 100Hz is restricted by the tool. This change makes perf stat -I possible on frequencies up to 1KHz and, to some extent, makes perf stat -I to be on-par with perf record sampling profiling. When running perf stat -I for monitoring e.g. PCIe uncore counters and at the same time profiling some I/O workload by perf record e.g. for cpu-cycles and context switches, it is then possible to observe consolidated CPU/OS/IO(Uncore) performance picture for that workload. Tool overhead warning printed when specifying -v option can be missed due to screen scrolling in case you have output to the console so message is moved into help available by running perf stat -h. Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/b842ad6a-d606-32e4-afe5-974071b5198e@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fix core dump when flag T is used

2018-03-16T16:55:29Z

Executing command 'perf stat -T -- ls' dumps core on x86 and s390. Here is the call back chain (done on x86): # gdb ./perf .... (gdb) r stat -T -- ls ... Program received signal SIGSEGV, Segmentation fault. 0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6 (gdb) where #0 0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6 #1 0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6 #2 0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580, list=0xbfb970, name=0xbf3ef0 "cpu", head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233 #3 0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580, list=0xbfb970, name=0xbf3ef0 "cpu", head_config=0xbfb930) at util/parse-events.c:1288 #4 0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580, scanner=0xbf4210) at util/parse-events.y:234 #5 0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0 "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673 #6 0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0 "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0) at util/parse-events.c:1713 #7 0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281 #8 0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at builtin-stat.c:2828 #9 0x00000000004c8b0f in run_builtin (p=0xab01a0 , argc=4, argv=0x7fffffffe3b0) at perf.c:297 #10 0x00000000004c8d7c in handle_internal_command (argc=4, argv=0x7fffffffe3b0) at perf.c:349 #11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c, argv=0x7fffffffe200) at perf.c:393 #12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537 (gdb) It turns out that a NULL pointer is referenced. Here are the function calls: ... cmd_stat() +---> add_default_attributes() +---> parse_events(evsel_list, transaction_attrs, NULL); 3rd parameter set to NULL Function parse_events(xx, xx, struct parse_events_error *err) dives into a bison generated scanner and creates parser state information for it first: struct parse_events_state parse_state = { .list = LIST_HEAD_INIT(parse_state.list), .idx = evlist->nr_entries, .error = err, <--- NULL POINTER !!! .evlist = evlist, }; Now various functions inside the bison scanner are called to end up in __parse_events_add_pmu(struct parse_events_state *parse_state, ..) with first parameter being a pointer to above structure definition. Now the PMU event name is not found (because being executed in a VM) and this function tries to create an error message with asprintf(&parse_state->error.str, ....) which references a NULL pointer and dumps core. Fix this by providing a pointer to the necessary error information instead of NULL. Technically only the else part is needed to avoid the core dump, just lets be safe... Signed-off-by: Thomas Richter Cc: Heiko Carstens Cc: Hendrik Brueckner Cc: Martin Schwidefsky Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Display pmu name when printing unmerged events in stat

2018-03-08T13:05:49Z

To simplify creation of events accross multiple instances of the same type of PMU stat supports two methods for creating multiple events from a single event specification: 1. A prefix or glob can be used in the PMU name. 2. Aliases, which are listed immediately after the Kernel PMU events by perf list, are used. When the --no-merge option is passed and these events are displayed individually the PMU name is lost and it's not possible to see which count corresponds to which pmu: $ perf stat -a -e l3cache/read-miss/ --no-merge ls > /dev/null Performance counter stats for 'system wide': 67 l3cache/read-miss/ 67 l3cache/read-miss/ 63 l3cache/read-miss/ 60 l3cache/read-miss/ 0.001675706 seconds time elapsed $ perf stat -a -e l3cache_read_miss --no-merge ls > /dev/null Performance counter stats for 'system wide': 12 l3cache_read_miss 17 l3cache_read_miss 10 l3cache_read_miss 8 l3cache_read_miss 0.001661305 seconds time elapsed This change adds the original pmu name to the event. For dynamic pmu events the pmu name is restored in the event name: $ perf stat -a -e l3cache/read-miss/ --no-merge ls > /dev/null Performance counter stats for 'system wide': 63 l3cache_0_3/read-miss/ 74 l3cache_0_1/read-miss/ 64 l3cache_0_2/read-miss/ 74 l3cache_0_0/read-miss/ 0.001675706 seconds time elapsed For alias events the name is added after the event name: $ perf stat -a -e l3cache_read_miss --no-merge ls > /dev/null Performance counter stats for 'system wide': 10 l3cache_read_miss [l3cache_0_3] 12 l3cache_read_miss [l3cache_0_1] 10 l3cache_read_miss [l3cache_0_2] 17 l3cache_read_miss [l3cache_0_0] 0.001661305 seconds time elapsed Signed-off-by: Agustin Vega-Frias Acked-by: Andi Kleen Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Timur Tabi Cc: linux-arm-kernel@lists.infradead.org Change-Id: I8056b9eda74bda33e95065056167ad96e97cb1fb Link: http://lkml.kernel.org/r/1520345084-42646-3-git-send-email-agustinv@codeaurora.org Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'perf/urgent' into perf/core, to resolve conflict

2018-03-07T08:23:12Z

Conflicts: tools/perf/perf.h Signed-off-by: Ingo Molnar

perf stat: Fix CVS output format for non-supported counters

2018-03-06T13:53:52Z

When printing stats in CSV mode, 'perf stat' appends extra separators when a counter is not supported: ,,L1-dcache-store-misses,mesos/bd442f34-2b4a-47df-b966-9b281f9f56fc,0,100.00,,,, Which causes a failure when parsing fields. The numbers of separators should be the same for each line, no matter if the counter is or not supported. Signed-off-by: Ilya Pronin Acked-by: Jiri Olsa Cc: Andi Kleen Link: http://lkml.kernel.org/r/20180306064353.31930-1-xiyou.wangcong@gmail.com Fixes: 92a61f6412d3 ("perf stat: Implement CSV metrics output") Signed-off-by: Cong Wang Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Ignore error thread when enabling system-wide --per-thread

2018-02-27T14:29:21Z

If we execute 'perf stat --per-thread' with non-root account (even set kernel.perf_event_paranoid = -1 yet), it reports the error: jinyao@skl:~$ perf stat --per-thread Error: You may not have permission to collect system-wide stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid, which controls use of the performance events system by unprivileged users (without CAP_SYS_ADMIN). The current value is 2: -1: Allow use of (almost) all events by all users Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK >= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN Disallow raw tracepoint access by users without CAP_SYS_ADMIN >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN To make this setting permanent, edit /etc/sysctl.conf too, e.g.: kernel.perf_event_paranoid = -1 Perhaps the ptrace rule doesn't allow to trace some processes. But anyway the global --per-thread mode had better ignore such errors and continue working on other threads. This patch will record the index of error thread in perf_evsel__open() and remove this thread before retrying. For example (run with non-root, kernel.perf_event_paranoid isn't set): jinyao@skl:~$ perf stat --per-thread ^C Performance counter stats for 'system wide': vmstat-3458 6.171984 cpu-clock:u (msec) # 0.000 CPUs utilized perf-3670 0.515599 cpu-clock:u (msec) # 0.000 CPUs utilized vmstat-3458 1,163,643 cycles:u # 0.189 GHz perf-3670 40,881 cycles:u # 0.079 GHz vmstat-3458 1,410,238 instructions:u # 1.21 insn per cycle perf-3670 3,536 instructions:u # 0.09 insn per cycle vmstat-3458 288,937 branches:u # 46.814 M/sec perf-3670 936 branches:u # 1.815 M/sec vmstat-3458 15,195 branch-misses:u # 5.26% of all branches perf-3670 76 branch-misses:u # 8.12% of all branches 12.651675247 seconds time elapsed Signed-off-by: Jin Yao Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Andi Kleen Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1516117388-10120-1-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Use xyarray dimensions to iterate fds

2018-02-21T14:36:57Z

Now that the xyarray stores the dimensions we can use those to iterate over the FDs for a evsel. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20171006020029.13339-1-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Add support to print counts after a period of time

2018-02-16T13:18:06Z

Introduce a new option to print counts after N milliseconds and update 'perf stat' documentation accordingly. Show below is the output of the new option for perf stat. $ perf stat --time 2000 -e cycles -a Performance counter stats for 'system wide': 157,260,423 cycles 2.003060766 seconds time elapsed We can print the count deltas after N milliseconds with this new introduced option. This option is not supported with "-I" option. In addition, according to Kangliang's patch(19afd10410957), the monitoring overhead for system-wide core event could be very high if the interval-print parameter was below 100ms, and the limitation value is 10ms. So the same warning will be displayed when the time is set between 10ms to 100ms, and the minimal time is limited to 10ms. Users can make a decision according to their spcific cases. Committer notes: This actually stops the workload after the specified time, then prints the counts. So I renamed the option to --timeout and updated the documentation to state that it will not just print the counts after the specified time, but will really stop the 'perf stat' session and print the counts. The rename from 'time' to 'timeout' also fixes the build in systems where 'time' is used by glibc and can't be used as a name of a variable, such as centos:5 and centos:6. Changes since v3: - none. Changes since v2: - modify the time check in __run_perf_stat func to keep some consistency with the workload case. - add the warning when the time is set between 10ms to 100ms. - add the pr_err when the time is set below 10ms. Changes since v1: - none. Signed-off-by: yuzhoujian Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: David Ahern Cc: Kan Liang Cc: Milian Wolff Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1517217923-8302-3-git-send-email-ufo19890607@gmail.com Signed-off-by: Arnaldo Carvalho de Melo