Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753959AbaF0ORY (ORCPT ); Fri, 27 Jun 2014 10:17:24 -0400 Received: from mail-ob0-f169.google.com ([209.85.214.169]:61994 "EHLO mail-ob0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753173AbaF0ORW convert rfc822-to-8bit (ORCPT ); Fri, 27 Jun 2014 10:17:22 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 27 Jun 2014 16:17:21 +0200 Message-ID: Subject: Re: [PERF_EVENT 3.11] Group Multiplexing not Working Properly From: Stephane Eranian To: =?UTF-8?B?THXDrXMgVGFuacOnYQ==?= Cc: LKML , Peter Zijlstra Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, Jun 24, 2014 at 7:36 PM, Luís Taniça wrote: > Hi, > > I am trying to configure 8 events in a machine which supports only 4 (so, using multiplexing). I tried different approaches: > > 1) Configure 8 events independently (works as expected) > 2) Configure 2 event-sets of 4 events each in counting mode (works as expected) > 3) Configure 2 event-sets of 4 events each in sampling mode (not working right) > What do it mean 'not working' in 3)? Are you using perf record or your own code? I think it would help if you could share the exact setup, i.e., the various struct perf_event_attr structs. > In case 3) I also tried different approaches: > > 3.a) 1 ring-buffer for each event-set and a callback for the POLL signal > - only the first ring-buffer was detecting samples > - the second ring-buffer was empty > > 3.b) 1 ring-buffer shared between event-sets (using PERF_EVENT_IOC_SET_OUTPUT) > - both event-sets were writing to the ring-buffer > - 1st event-set only writes 2 samples while 2nd event-set writes like 20+ samples > - samples from 1st event-set report time_enabled=time_running while samples from 2nd don’t > > Moreover, in both cases the wakeup_events parameter is not working. > I believe there must be some programming bugs in perf_event while profiling in sampling mode with multiple event-sets (groups). > > Regards, > matallui > > -- 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/