All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Pádraig Brady" <P@draigBrady.com>
To: linux-perf-users@vger.kernel.org
Subject: PEBS availability
Date: Tue, 24 May 2011 16:49:27 +0100	[thread overview]
Message-ID: <4DDBD387.2070906@draigBrady.com> (raw)

Hi,

I've just got a shiny new i3-2310M and am a
bit surprised that `perf` isn't listing
detailed stats like L1 cache misses etc.

$ perf stat true

 Performance counter stats for 'true':

             1,239 cache-misses             #      1.555 M/sec
             9,314 cache-references         #     11.693 M/sec
             3,940 branch-misses            #      4.871 %
            80,885 branches                 #    101.546 M/sec
           403,808 instructions             #      0.000 IPC
     <not counted> cycles
                81 page-faults              #      0.102 M/sec
                 0 CPU-migrations           #      0.000 M/sec
                 1 context-switches         #      0.001 M/sec
          0.796537 task-clock-msecs         #      0.032 CPUs

        0.024654938  seconds time elapsed

I searched for a while but found it _very_ difficult
to find info on what was available on particular intel CPUs.

I did see in the "Nehalem Core PMU programming guide":
http://software.intel.com/file/30320
that the above stats are core features and that the other
counters I mentioned are PEBS (Precise Event Based Sampling)
and are not available on all systems.

So am I out of look with my new i3 sandy bridge CPU?
Are PEBS restricted to i7 versions only?
Is this documented anywhere?

Maybe I need some kernel support as hinted at by:
http://lwn.net/Articles/430100/
My kernel is 2.6.38.6-27.fc15.x86_64

cheers.
Pádraig.

             reply	other threads:[~2011-05-24 15:51 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-24 15:49 Pádraig Brady [this message]
2011-05-24 17:26 ` PEBS availability David Ahern
2011-05-24 20:37 ` Arun Sharma
2011-05-25  8:33   ` Pádraig Brady
2011-05-27 10:13   ` Pádraig Brady

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4DDBD387.2070906@draigBrady.com \
    --to=p@draigbrady.com \
    --cc=linux-perf-users@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.