Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751992Ab2JVILv (ORCPT ); Mon, 22 Oct 2012 04:11:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43892 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751245Ab2JVILu (ORCPT ); Mon, 22 Oct 2012 04:11:50 -0400 Date: Mon, 22 Oct 2012 10:09:31 +0200 From: Jiri Olsa To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Paul Mackerras , Corey Ashford , Frederic Weisbecker , Namhyung Kim Subject: Re: [PATCH 00/11] perf tool: Add PERF_SAMPLE_READ sample read support Message-ID: <20121022080930.GB984@krava.brq.redhat.com> References: <1350743599-4805-1-git-send-email-jolsa@redhat.com> <20121021163848.GB28726@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121021163848.GB28726@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3194 Lines: 82 On Sun, Oct 21, 2012 at 06:38:49PM +0200, Ingo Molnar wrote: > > * Jiri Olsa wrote: > > > hi, > > adding support to read sample values through the PERF_SAMPLE_READ > > sample type. It's now possible to specify 'S' modifier for an event > > and get its sample value by PERF_SAMPLE_READ. > > > > For group the 'S' modifier will enable sampling only for the leader > > and read all the group member by PERF_SAMPLE_READ smple type with > > PERF_FORMAT_GROUP read format. > > > > This patchset is based on group report patches by Namhyung Kim: > > http://lwn.net/Articles/518569/ > > > > Example: > > (making sample on cycles, reading both cycles and cache-misses > > by PERF_SAMPLE_READ/PERF_FORMAT_GROUP) > > > > # ./perf record -e '{cycles,cache-misses}:S' ls > > ... > > > > # ./perf report --group --show-total-period --stdio > > # ======== > > # captured on: Sat Oct 20 16:53:39 2012 > > ... > > # group: {cycles,cache-misses} > > # ======== > > # > > # Samples: 86 of event 'anon group { cycles, cache-misses }' > > # Event count (approx.): 34863674 > > # > > # Overhead Period Command Shared Object Symbol > > # ................ ........................ ....... ................. ................................ > > Might make sense to consider this column enumeration: > > # > # cycles > # | cache-misses > # | | > > # v v > > # > > 16.56% 19.47% 5773450 475 ls [kernel.kallsyms] [k] native_sched_clock > > 10.87% 0.74% 3789088 18 ls [kernel.kallsyms] [k] rtl8169_interrupt no problem in '--stdio' mode I guess.. not sure in '--tui/--gtk', Namhyung? > > 9.82% 15.86% 3423364 387 ls [kernel.kallsyms] [k] mark_lock > > 8.43% 17.75% 2938384 433 ls ld-2.14.90.so [.] do_lookup_x > > 6.79% 20.86% 2365622 509 ls ls [.] calculate_columns > > 6.36% 0.61% 2216808 15 ls [kernel.kallsyms] [k] lock_release > > ... > > /me wants this feature ASAP :-) > > This should probably be the out of box default for perf record > and perf top as well - the cache miss rate is probably one of > the least appreciated aspects of overhead analysis. > > Does it have sane output if the cache-misses event is not > supported? The cache-misses column should probably stay empty in > that case - basically falling back to today's default output. unsupported counters fail before report: # ./perf record -e '{cycles,stalled-cycles-backend}:S' ls Error: The stalled-cycles-backend event is not supported. ls: Terminated similar for top, so we'd need special treatment for default thanks, jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/