From 860f9f6b02e9e846c4cfb3505efed331a910d0b7 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 15 Jan 2018 20:51:48 -0600 Subject: 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 Signed-off-by: Steven Rostedt (VMware) --- Documentation/trace/histogram.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') 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 -- cgit