linux-kernel - Re: perf tools miscellaneous questions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 05 Nov 2010 13:38:12 +0100
From:	Francis Moreau <francis.moro@...il.com>
To:	Victor Jimenez <victor.javier@....es>
Cc:	Reid Kleckner <reid.kleckner@...il.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Stephane Eranian <eranian@...gle.com>,
	linux-perf-users@...r.kernel.org
Subject: Re: perf tools miscellaneous questions

Victor Jimenez <victor.javier@....es> writes:

[...]

> If you are measuring last level cache misses, I would recommend you to
> use a memory intensive application/benchmark instead of /bin/true, as
> otherwise there can be a significant variation between two runs.

I agree.

But still with intensive application, I got the same results:


  $ perf stat -r3 -e cache-misses:u gzip -9 -c vmlinux.o >/dev/null

   Performance counter stats for 'gzip -9 -c vmlinux.o' (3 runs):

               950704  cache-misses               ( +-  24.925% )

         82.619412905  seconds time elapsed   ( +-   0.072% )


  $ perf stat -r3 -e llc-load-misses:u,llc-store-misses:u gzip -9 -c vmlinux.o >/dev/null

   Performance counter stats for 'gzip -9 -c vmlinux.o' (3 runs):
  
               317054  LLC-load-misses            ( +-  11.758% )
               162634  LLC-store-misses           ( +-   9.700% )

         82.657099783  seconds time elapsed   ( +-   0.167% )

Thanks
-- 
Francis
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/