Re: [RFC][PATCH 00/21] tracing: Inter-event (e.g. latency) support

From: Steven Rostedt
Date: Thu Feb 09 2017 - 14:57:44 EST


On Thu, 09 Feb 2017 11:18:32 -0600
Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> wrote:

> I think it might make a lot of sense at this point to actually create a
> system-wide list of active triggers e.g. tracing/events/triggers or
> something like that. It's something I've kind of wanted anyway, and
> would be really useful if not indispensable for this. Actually, I
> thought it might even be nice to have some kind of mini-fs or something
> making it easy to group sets of related triggers and enable and
> disable/remove them as a group, but a simple list would suffice too...

Note, (new) trace-cmd does this for you (by querying all trigger files).

# echo 'stacktrace if COMM ~ "system*"' > /debug/tracing/events/syscalls/sys_enter_open/trigger
# trace-cmd stat

Events:
(none enabled)

Triggers:
syscalls:sys_enter_open "stacktrace:unlimited if COMM ~ "system*""

Tracing is enabled



-- Steve