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From: David Ahern <dsahern@gmail.com>
To: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Stephane Eranian <eranian@gmail.com>,
	Jiri Olsa <jolsa@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: perf/ftrace: does PERF_EVENT_IOC_SET_FILTER serve any purpose?
Date: Tue, 09 Jun 2015 13:59:01 -0600	[thread overview]
Message-ID: <55774585.7030000@gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1506091558010.9662@vincent-weaver-1.umelst.maine.edu>

On 6/9/15 2:02 PM, Vince Weaver wrote:
> # ls/sys/kernel/debug/tracing/events/irq/irq_handler_entry/
> enable	filter	format	id  trigger
>
> # perf list
> ....
>    [ Tracepoints not available: No such file or directory ]
>
> strace shows
> statfs("/sys/kernel/debug/tracing/events", {f_type=0x74726163,
> f_bsize=4096, f_blocks=0, f_bfree=0, f_bavail=0, f_files=0, f_ffree=0,
> f_fsid={0, 0}, f_namelen=255, f_frsize=4096}) = 0
>
> so I have no idea what's going wrong here.

Check Steven's email; probably the issue.

>
>
> Anyway, on a related question, I see for the event that you use
> 	--filter irq==28
> How do I find out the valid filters for each event?  Do I have to parse
> the "format" file under
> 	/sys/kernel/debug/tracing/events/*/* ?

Yes. And *very important* don't use the print fmt names, but the field 
names. Often they are the same but when they differ it can be maddening.

  reply	other threads:[~2015-06-09 19:59 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-09 18:30 perf/ftrace: does PERF_EVENT_IOC_SET_FILTER serve any purpose? Vince Weaver
2015-06-09 19:25 ` David Ahern
2015-06-09 19:51   ` Vince Weaver
2015-06-09 19:49     ` David Ahern
2015-06-09 20:02       ` Vince Weaver
2015-06-09 19:59         ` David Ahern [this message]
2015-06-09 20:18           ` Vince Weaver
2015-06-09 19:55     ` Steven Rostedt
2015-06-09 20:07       ` Vince Weaver
2015-06-09 20:11         ` Arnaldo Carvalho de Melo
2015-06-10  6:51       ` Ingo Molnar

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