From: Andi Kleen <andi@firstfloor.org>
To: Noah Luther <nluther@vt.edu>
Cc: linux-perf-users@vger.kernel.org
Subject: Re: perf branch
Date: Mon, 14 Apr 2014 10:41:07 -0700 [thread overview]
Message-ID: <87a9bnizbg.fsf@tassilo.jf.intel.com> (raw)
In-Reply-To: <CAH+i1GK4QdEzoa05PUN-Zx8Gzr2-w0RY631a9MzvTvyMAs1fGg@mail.gmail.com> (Noah Luther's message of "Sun, 13 Apr 2014 23:55:53 -0400")
Noah Luther <nluther@vt.edu> writes:
> Hello,
>
> I am trying to use perf to trace branches as described by the 'perf
> branch' subcommand. Is there support through perf_event_open to access
> the buffer storing branch traces? I saw Akihiro Nagai's presentation
> on 'perf branch', but haven't yet figured out how to enable BTS and
> access the buffer based on the documentation on this page:
>
> http://web.eece.maine.edu/~vweaver/projects/perf_events/perf_event_open.html
>
> If there are any resources that might be of use to me, I would
> appreciate any assistance.
perf branch never made it, but you can use
perf record -e branches:u -c1 ...
perf script
Also the latest GDB snapshots have builtin support for BTS through
perf in a somewhat more convenient interface.
Keep in mind that BTS is quite slow and often cannot keep up.
In the future ProcessorTrace will be better.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
prev parent reply other threads:[~2014-04-14 17:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-14 3:55 perf branch Noah Luther
2014-04-14 12:53 ` Christopher Covington
2014-04-14 17:41 ` Andi Kleen [this message]
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