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| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2018-01-16 03:51:48 +0100 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-03-10 22:05:54 +0100 |
| commit | 860f9f6b02e9e846c4cfb3505efed331a910d0b7 (patch) | |
| tree | 2fc04be64e2ba47c05d7ce356bf0652012b43437 /Documentation/trace | |
| parent | tracing: Add hist_data member to hist_field (diff) | |
| download | linux-860f9f6b02e9e846c4cfb3505efed331a910d0b7.tar.xz linux-860f9f6b02e9e846c4cfb3505efed331a910d0b7.zip | |
tracing: Add usecs modifier for hist trigger timestamps
Appending .usecs onto a common_timestamp field will cause the
timestamp value to be in microseconds instead of the default
nanoseconds. A typical latency histogram using usecs would look like
this:
# echo 'hist:keys=pid,prio:ts0=common_timestamp.usecs ...
# echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 ...
This also adds an external trace_clock_in_ns() to trace.c for the
timestamp conversion.
Link: http://lkml.kernel.org/r/4e813705a170b3e13e97dc3135047362fb1a39f3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/histogram.txt | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt index a4143f04a097..25c94730d3fe 100644 --- a/Documentation/trace/histogram.txt +++ b/Documentation/trace/histogram.txt @@ -74,6 +74,7 @@ .syscall display a syscall id as a system call name .execname display a common_pid as a program name .log2 display log2 value rather than raw number + .usecs display a common_timestamp in microseconds Note that in general the semantics of a given field aren't interpreted when applying a modifier to it, but there are some |