Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757102Ab3JIJy2 (ORCPT ); Wed, 9 Oct 2013 05:54:28 -0400 Received: from mail-ee0-f44.google.com ([74.125.83.44]:53063 "EHLO mail-ee0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753241Ab3JIJy1 (ORCPT ); Wed, 9 Oct 2013 05:54:27 -0400 Date: Wed, 9 Oct 2013 11:54:23 +0200 From: Ingo Molnar To: David Ahern Cc: Stephane Eranian , LKML , Peter Zijlstra , "mingo@elte.hu" , "ak@linux.intel.com" , Arnaldo Carvalho de Melo , Jiri Olsa , Hugh Dickins Subject: Re: [RFC] perf: mmap2 not covering VM_CLONE regions Message-ID: <20131009095423.GA17480@gmail.com> References: <52541556.5060907@gmail.com> <20131008194129.GC7315@gmail.com> <525463B7.3030203@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <525463B7.3030203@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: 1481 Lines: 36 * David Ahern wrote: > On 10/8/13 1:54 PM, Stephane Eranian wrote: > >>>If the current MMAP2 is not a complete solution for what you (Google) > >>>need, should support be reverted before 3.12 is released? No sense in > >>>making this part of the forever API if more work is needed on it. > >> > >>Instead of a full revert we could just turn off the ABI portion minimally > >>and not recognize it for now. Assuming a more complete solution is in the > >>works for v3.13. > >> > >That's a possibility. They are also pieces in the perf tool itself. > >We could certainly make the attr->mmap2 bit disappear. > > > >I think it boils down to how can we uniquely identify virtual > >mapping to the same physical data either via shmat(), files, VM_CLONE. > >We had all covered but the last case with the ino approach. We don't have > >a solution for VM_CLONE yet. > > > > I was mainly thinking the 2 parts that generate MMAP2 events: kernel > side it's the mmap2 attribute and perf_event_mmap_output; userspace side > it's perf_event__synthesize_mmap_event. Certainly the rest of the > plumbing can be left in place until the solution is refined as needed. Could some of you please send a patch ASAP? Thanks, Ingo -- 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/