Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756456AbZFWI0x (ORCPT ); Tue, 23 Jun 2009 04:26:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751898AbZFWI0e (ORCPT ); Tue, 23 Jun 2009 04:26:34 -0400 Received: from bilbo.ozlabs.org ([203.10.76.25]:49477 "EHLO bilbo.ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751642AbZFWI0d (ORCPT ); Tue, 23 Jun 2009 04:26:33 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <19008.37301.779108.964118@cargo.ozlabs.ibm.com> Date: Tue, 23 Jun 2009 18:26:29 +1000 From: Paul Mackerras To: eranian@gmail.com Cc: Ingo Molnar , LKML , Andrew Morton , Thomas Gleixner , Robert Richter , Peter Zijlstra , Andi Kleen , Maynard Johnson , Carl Love , Corey J Ashford , Philip Mucci , Dan Terpstra , perfmon2-devel Subject: Re: I.2 - Grouping In-Reply-To: <7c86c4470906230036o677e6c48j923a7431b9912372@mail.gmail.com> References: <7c86c4470906161042p7fefdb59y10f8ef4275793f0e@mail.gmail.com> <20090622115017.GC24366@elte.hu> <19008.25905.550815.222975@drongo.ozlabs.ibm.com> <7c86c4470906230036o677e6c48j923a7431b9912372@mail.gmail.com> X-Mailer: VM 8.0.12 under 22.2.1 (i486-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 588 Lines: 18 stephane eranian writes: > What happens if I do: > fd0 = perf_counter_open(&hwc1, getpid(), -1, -1, 0); > fd1 = perf_counter_open(&hwc2, getpid(), -1, fd0, 0); > > And then: > fd2 = perf_counter_open(&hwc2, getpid(), -1, fd1, 0); That perf_counter_open call will fail with an EINVAL error because fd1 is not a group leader. Paul. -- 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/