Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756100Ab2EGNDR (ORCPT ); Mon, 7 May 2012 09:03:17 -0400 Received: from merlin.infradead.org ([205.233.59.134]:59033 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752056Ab2EGNDQ (ORCPT ); Mon, 7 May 2012 09:03:16 -0400 Subject: Re: [PATCH 4/7] perf/x86-ibs: Add support for IBS pseudo events From: Peter Zijlstra To: Robert Richter Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Stephane Eranian , Jiri Olsa , LKML In-Reply-To: <1335983192-23731-5-git-send-email-robert.richter@amd.com> References: <1335983192-23731-1-git-send-email-robert.richter@amd.com> <1335983192-23731-5-git-send-email-robert.richter@amd.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 07 May 2012 15:03:02 +0200 Message-ID: <1336395782.27020.37.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1014 Lines: 26 On Wed, 2012-05-02 at 20:26 +0200, Robert Richter wrote: > +enum ibs_filter_type { > + IBS_NO_FILTER = 0, > + IBS_MATCH_FILTER = 1, > + IBS_ANY_SET_FILTER = 2, > + IBS_PSEUDO_EVENT = 0x0F, > +}; I don't get how those pseudo events work, AFAIKT IBS_PSEUDO_EVENT causes one to loose all events since it does have a filter set but fails the filter and thus we skip the call to perf_event_overflow(). Furthermore, I think this filter stuff should accumulate the period so that PERF_SAMPLE_PERIOD still works correctly and reflects the number of counts since the last sample. Also, what's the point of filtering in-kernel as opposed to doing all this in userspace? Is the amount of data 'saved' significant enough? -- 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/