diff options
| author | Changbin Du <changbin.du@gmail.com> | 2020-08-08 10:31:27 +0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-08-14 08:37:46 -0300 |
| commit | 846e1939801a0893ea71a6a56d8dbe2bf46682d1 (patch) | |
| tree | cb175671eb137af8808c8a5c3a5fc5a0401b93c8 /tools/perf/Documentation | |
| parent | 68faab0f934d83d374b3d696d861d8502641fa19 (diff) | |
perf ftrace: Add option '-m/--buffer-size' to set per-cpu buffer size
This adds an option '-m/--buffer-size' to allow us set the size of per-cpu
tracing buffer.
Committer testing:
Before running with this option:
# find /sys/kernel/tracing/ -name buffer_size_kb | xargs cat
1408
1408
1408
1408
1408
1408
1408
1408
1408
#
Then, run:
# perf ftrace -m 2048K | head -10
2) | mutex_unlock() {
2) ==========> |
2) | smp_irq_work_interrupt() {
2) | irq_enter() {
2) 0.121 us | rcu_irq_enter();
2) 0.128 us | irqtime_account_irq();
2) 0.719 us | }
2) | __wake_up() {
2) | __wake_up_common_lock() {
2) 0.105 us | _raw_spin_lock_irqsave();
#
Now look at those tracefs knobs:
# find /sys/kernel/tracing/ -name buffer_size_kb | xargs cat
2048
2048
2048
2048
2048
2048
2048
2048
2048
#
This should be similar to the -m option in the other perf tools, such as
'perf record', 'perf trace', etc.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lore.kernel.org/lkml/20200808023141.14227-5-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-ftrace.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 4f5628445a63..7a5d915f60b0 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -53,6 +53,11 @@ OPTIONS Ranges of CPUs are specified with -: 0-2. Default is to trace on all online CPUs. +-m:: +--buffer-size:: + Set the size of per-cpu tracing buffer, <size> is expected to + be a number with appended unit character - B/K/M/G. + -T:: --trace-funcs=:: Select function tracer and set function filter on the given |