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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-01-22 15:38:54 +0100 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-01-25 10:37:29 +0100 |
| commit | 591421e151ddf95e43d690a5c9b291d8e1cb8065 (patch) | |
| tree | 0f0f72383428481f380f4afe989a22adbf03aef9 /tools/perf/Documentation/perf-trace.txt | |
| parent | perf bpf: Remove misplaced __maybe_unused attribute (diff) | |
| download | linux-591421e151ddf95e43d690a5c9b291d8e1cb8065.tar.xz linux-591421e151ddf95e43d690a5c9b291d8e1cb8065.zip | |
perf trace: Add --print-sample
To help with debugging, like the interrupted out of order issue that
will be dealt with in the next patch in this series, changing the code
to deal with:
raw_syscalls:sys_enter 411967179.269 Timer 9609/9626 [2]
raw_syscalls:sys_enter 411967179.213 file:// Content 9609/9609 [3]
328.038 (18446744073709.496 ms): Timer/9626 futex(uaddr: 0x7fc0d4027044, op: WAIT|PRIV, utime: 0x7fc0b0ffdb50 ) ...
raw_syscalls:sys_exit 411967179.225 file:// Content 9609/9609 [3]
327.982 ( 0.012 ms): file:// Conten/9609 futex(uaddr: 0x7fc0d4027040, op: WAKE|PRIV, val: 1 ) = 1
That long duration is the bug.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-fljqiibjn7wet24jd1ed7abc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation/perf-trace.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-trace.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index 6909cf1e0eea..33a88e984e66 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -163,6 +163,10 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs. Implies '--call-graph dwarf' when --call-graph not present on the command line, on systems where DWARF unwinding was built in. +--print-sample:: + Print the PERF_RECORD_SAMPLE PERF_SAMPLE_ info for the + raw_syscalls:sys_{enter,exit} tracepoints, for debugging. + --proc-map-timeout:: When processing pre-existing threads /proc/XXX/mmap, it may take a long time, because the file may be huge. A time out is needed in such cases. |