From 8b7622bf94a44b3f912e6492bf500e86171300b8 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 15 Jan 2018 20:52:03 -0600 Subject: tracing: Add cpu field for hist triggers A common key to use in a histogram is the cpuid - add a new cpu 'synthetic' field named 'cpu' for that purpose. Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware) --- Documentation/trace/histogram.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'Documentation') diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt index 25c9473..be612ca 100644 --- a/Documentation/trace/histogram.txt +++ b/Documentation/trace/histogram.txt @@ -172,6 +172,21 @@ The examples below provide a more concrete illustration of the concepts and typical usage patterns discussed above. + 'special' event fields + ------------------------ + + There are a number of 'special event fields' available for use as + keys or values in a hist trigger. These look like and behave as if + they were actual event fields, but aren't really part of the event's + field definition or format file. They are however available for any + event, and can be used anywhere an actual event field could be. + They are: + + common_timestamp u64 - timestamp (from ring buffer) associated + with the event, in nanoseconds. May be + modified by .usecs to have timestamps + interpreted as microseconds. + cpu int - the cpu on which the event occurred. 6.2 'hist' trigger examples --------------------------- -- cgit v1.1