Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753962Ab0FPOy1 (ORCPT ); Wed, 16 Jun 2010 10:54:27 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:44688 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751228Ab0FPOy0 convert rfc822-to-8bit (ORCPT ); Wed, 16 Jun 2010 10:54:26 -0400 Subject: Re: [RFC] perf/perf_events: misleading number of samples due to mmap() From: Peter Zijlstra To: Stephane Eranian Cc: Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, mingo@elte.hu, paulus@samba.org, davem@davemloft.net, fweisbec@gmail.com, perfmon2-devel@lists.sf.net, eranian@gmail.com In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Wed, 16 Jun 2010 16:54:12 +0200 Message-ID: <1276700052.1745.600.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 642 Lines: 13 On Wed, 2010-06-16 at 16:40 +0200, Stephane Eranian wrote: > The reason is that perf reports an estimate based on the > number of bytes written to the buffer divided by the minimal > sample size of 24 bytes. Right, we should change that based on the PERF_SAMPLE flags used. It will remain an estimate due to the out of band events, but it should be closer than assuming the minimal sample size. -- 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/