From a9c5e6c1e9bff42ca5f01ceb3092a27a010755fb Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 22 Oct 2018 14:14:16 -0300 Subject: [PATCH] perf trace: Introduce per-event maximum number of events property Call it 'nr', as in this context it should be expressive enough, i.e.: # perf trace -e sched:*waking/nr=8,call-graph=fp/ 0.000 :0/0 sched:sched_waking:comm=rcu_sched pid=10 prio=120 target_cpu=001 try_to_wake_up ([kernel.kallsyms]) sched_clock ([kernel.kallsyms]) 3.933 :0/0 sched:sched_waking:comm=rcu_sched pid=10 prio=120 target_cpu=001 try_to_wake_up ([kernel.kallsyms]) sched_clock ([kernel.kallsyms]) 3.970 IPDL Backgroun/3622 sched:sched_waking:comm=Gecko_IOThread pid=3569 prio=120 target_cpu=003 try_to_wake_up ([kernel.kallsyms]) __libc_write (/usr/lib64/libpthread-2.26.so) 20.069 IPDL Backgroun/3622 sched:sched_waking:comm=Gecko_IOThread pid=3569 prio=120 target_cpu=003 try_to_wake_up ([kernel.kallsyms]) __libc_write (/usr/lib64/libpthread-2.26.so) 37.170 IPDL Backgroun/3622 sched:sched_waking:comm=Gecko_IOThread pid=3569 prio=120 target_cpu=003 try_to_wake_up ([kernel.kallsyms]) __libc_write (/usr/lib64/libpthread-2.26.so) 53.267 IPDL Backgroun/3622 sched:sched_waking:comm=Gecko_IOThread pid=3569 prio=120 target_cpu=003 try_to_wake_up ([kernel.kallsyms]) __libc_write (/usr/lib64/libpthread-2.26.so) 70.365 IPDL Backgroun/3622 sched:sched_waking:comm=Gecko_IOThread pid=3569 prio=120 target_cpu=003 try_to_wake_up ([kernel.kallsyms]) __libc_write (/usr/lib64/libpthread-2.26.so) 75.781 Web Content/3649 sched:sched_waking:comm=JS Helper pid=3670 prio=120 target_cpu=000 try_to_wake_up ([kernel.kallsyms]) try_to_wake_up ([kernel.kallsyms]) wake_up_q ([kernel.kallsyms]) futex_wake ([kernel.kallsyms]) do_futex ([kernel.kallsyms]) __x64_sys_futex ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) pthread_cond_signal@@GLIBC_2.3.2 (/usr/lib64/libpthread-2.26.so) # # perf trace -e sched:*switch/nr=2/,block:*_plug/nr=4/,block:*_unplug/nr=1/,net:*dev_queue/nr=3,max-stack=16/ 0.000 :0/0 sched:sched_switch:swapper/0:0 [120] S ==> trace:3367 [120] 0.046 :0/0 sched:sched_switch:swapper/1:0 [120] S ==> kworker/u16:58:2722 [120] 570.670 irq/50-iwlwifi/680 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051ef00 len=66 __dev_queue_xmit ([kernel.kallsyms]) 1106.141 jbd2/dm-0-8/476 block:block_plug:[jbd2/dm-0-8] 1106.175 jbd2/dm-0-8/476 block:block_unplug:[jbd2/dm-0-8] 1 1618.088 kworker/u16:30/2694 block:block_plug:[kworker/u16:30] 1810.000 :0/0 net:net_dev_queue:dev=vnet0 skbaddr=0xffff93498051ef00 len=52 __dev_queue_xmit ([kernel.kallsyms]) 3857.974 :0/0 net:net_dev_queue:dev=vnet0 skbaddr=0xffff93498051f900 len=52 __dev_queue_xmit ([kernel.kallsyms]) 4790.277 jbd2/dm-2-8/748 block:block_plug:[jbd2/dm-2-8] 4790.448 jbd2/dm-2-8/748 block:block_plug:[jbd2/dm-2-8] # The global --max-events has precendence: # trace --max-events 3 -e sched:*switch/nr=2/,block:*_plug/nr=4/,block:*_unplug/nr=1/,net:*dev_queue/nr=3,max-stack=16/ 0.000 :0/0 sched:sched_switch:swapper/0:0 [120] S ==> qemu-system-x86:2252 [120] 0.029 qemu-system-x8/2252 sched:sched_switch:qemu-system-x86:2252 [120] D ==> swapper/0:0 [120] 58.047 DNS Res~er #14/31661 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff9346966af100 len=84 __dev_queue_xmit ([kernel.kallsyms]) __libc_send (/usr/lib64/libpthread-2.26.so) # Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-s4jswltvh660ughvg9nwngah@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-trace.txt | 20 ++++++++++++++++++++ tools/perf/builtin-trace.c | 19 +++++++++++++++++-- tools/perf/util/evsel.h | 1 + 3 files changed, 38 insertions(+), 2 deletions(-) diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index 0d1a1cd4d328..e113450503d2 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -285,6 +285,26 @@ Trace the next min page page fault to take place on the first CPU: [0x18b26e6bc2bd] (/tmp/perf-17136.map) # +Trace the next two sched:sched_switch events, four block:*_plug events, the +next block:*_unplug and the next three net:*dev_queue events, this last one +with a backtrace of at most 16 entries, system wide: + + # perf trace -e sched:*switch/nr=2/,block:*_plug/nr=4/,block:*_unplug/nr=1/,net:*dev_queue/nr=3,max-stack=16/ + 0.000 :0/0 sched:sched_switch:swapper/2:0 [120] S ==> rcu_sched:10 [120] + 0.015 rcu_sched/10 sched:sched_switch:rcu_sched:10 [120] R ==> swapper/2:0 [120] + 254.198 irq/50-iwlwifi/680 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051f600 len=66 + __dev_queue_xmit ([kernel.kallsyms]) + 273.977 :0/0 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051f600 len=78 + __dev_queue_xmit ([kernel.kallsyms]) + 274.007 :0/0 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051ff00 len=78 + __dev_queue_xmit ([kernel.kallsyms]) + 2930.140 kworker/u16:58/2722 block:block_plug:[kworker/u16:58] + 2930.162 kworker/u16:58/2722 block:block_unplug:[kworker/u16:58] 1 + 4466.094 jbd2/dm-2-8/748 block:block_plug:[jbd2/dm-2-8] + 8050.123 kworker/u16:30/2694 block:block_plug:[kworker/u16:30] + 8050.271 kworker/u16:30/2694 block:block_plug:[kworker/u16:30] + # + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-script[1] diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 589e0412652a..7081d7ea12e5 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -2092,8 +2092,18 @@ static int trace__event_handler(struct trace *trace, struct perf_evsel *evsel, union perf_event *event __maybe_unused, struct perf_sample *sample) { - struct thread *thread = machine__findnew_thread(trace->host, sample->pid, sample->tid); + struct thread *thread; int callchain_ret = 0; + /* + * Check if we called perf_evsel__disable(evsel) due to, for instance, + * this event's max_events having been hit and this is an entry coming + * from the ring buffer that we should discard, since the max events + * have already been considered/printed. + */ + if (evsel->disabled) + return 0; + + thread = machine__findnew_thread(trace->host, sample->pid, sample->tid); if (sample->callchain) { callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor); @@ -2142,6 +2152,11 @@ static int trace__event_handler(struct trace *trace, struct perf_evsel *evsel, sample->raw_data, sample->raw_size, trace->output); ++trace->nr_events_printed; + + if (evsel->max_events != ULONG_MAX && ++evsel->nr_events_printed == evsel->max_events) { + perf_evsel__disable(evsel); + perf_evsel__close(evsel); + } } } @@ -2726,7 +2741,7 @@ next_event: int timeout = done ? 100 : -1; if (!draining && perf_evlist__poll(evlist, timeout) > 0) { - if (perf_evlist__filter_pollfd(evlist, POLLERR | POLLHUP) == 0) + if (perf_evlist__filter_pollfd(evlist, POLLERR | POLLHUP | POLLNVAL) == 0) draining = true; goto again; diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 4ef50f157b50..3147ca76c6fc 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -102,6 +102,7 @@ struct perf_evsel { int idx; u32 ids; unsigned long max_events; + unsigned long nr_events_printed; char *name; double scale; const char *unit; -- 2.11.0