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authorArnaldo Carvalho de Melo <acme@redhat.com>2018-01-22 11:38:54 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2018-01-25 06:37:29 -0300
commit591421e151ddf95e43d690a5c9b291d8e1cb8065 (patch)
tree0f0f72383428481f380f4afe989a22adbf03aef9 /tools/perf/Documentation
parent78c436907c94660edc76f499b80dbebbbe6fd572 (diff)
downloadlinux-591421e151ddf95e43d690a5c9b291d8e1cb8065.tar.bz2
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')
-rw-r--r--tools/perf/Documentation/perf-trace.txt4
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.