On Fri, 22 Sep 2017 15:00:06 -0500 Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> wrote: > A common key to use in a histogram is the cpuid - add a new cpu > 'synthetic' field for that purpose. This field is named cpu rather > than $cpu or $common_cpu because 'cpu' already exists as a special > filter field and it makes more sense to match that rather than add > another name for the same thing. > > Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> > --- > Documentation/trace/events.txt | 18 ++++++++++++++++++ > kernel/trace/trace_events_hist.c | 28 +++++++++++++++++++++++++++- > 2 files changed, 45 insertions(+), 1 deletion(-) > > diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt > index 2cc08d4..f36fa00 100644 > --- a/Documentation/trace/events.txt > +++ b/Documentation/trace/events.txt > @@ -668,6 +668,24 @@ The following commands are supported: > The examples below provide a more concrete illustration of the > concepts and typical usage patterns discussed above. > > + 'special' event fields > + ------------------------ > + > + There are a number of 'special event fields' available for use as > + keys or values in a hist trigger. These look like and behave as if > + they were actual event fields, but aren't really part of the event's > + field definition or format file. They are however available for any > + event, and can be used anywhere an actual event field could be. > + 'Special' field names are always prefixed with a '$' character to > + indicate that they're not normal fields (with the exception of > + 'cpu', for compatibility with existing filter usage): > + > + $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. > + > You were going to update this too. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
