Message-ID: <50350F2D.6030408@gmail.com>
Date: Wed, 22 Aug 2012 10:56:13 -0600
From: David Ahern <dsahern@gmail.com>
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To: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
CC: Luigi Semenzato <semenzato@chromium.org>, Ingo Molnar <mingo@kernel.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@elte.hu>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vasiliy Kulikov <segoon@openwall.com>,
        Stephen Wilson <wilsons@start.ca>, Oleg Nesterov <oleg@redhat.com>,
        Tejun Heo <tj@kernel.org>,
        Paul Gortmaker <paul.gortmaker@windriver.com>,
        Andi Kleen <ak@linux.intel.com>,
        Lucas De Marchi <lucas.demarchi@profusion.mobi>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        "Rafael J. Wysocki" <rjw@sisk.pl>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Namhyung Kim <namhyung@gmail.com>,
        Robert Richter <robert.richter@amd.com>, linux-kernel@vger.kernel.org,
        sonnyrao@chromium.org, olofj@chromium.org, eranian@google.com
Subject: Re: [PATCH] perf: do not flush maps on COMM for perf report
References: <1345585940-6497-1-git-send-email-semenzato@chromium.org> <20120822072822.GA11042@gmail.com> <CAA25o9RJOre2mw4z7Mh94iRKcHVdby9RjLfP91far16me8_94Q@mail.gmail.com> <20120822162958.GA13623@infradead.org>
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On 8/22/12 10:29 AM, Arnaldo Carvalho de Melo wrote:
> Adding the EXEC event, ditto. And I agree that while adding it we want
> to do 1/2 as pre-requisite.

maps should not be flushed on a COMM event, so that was a mistake. Given 
that what new information does an EXEC event provide? Same process id. A 
COMM event is generated on an exec, so the name change happens. Mappings 
are dropped prior to that - and there is no unmap event. That seems to 
be a missing piece. Maps are added which is handled by MMAP events. 
After that why is an exec event relevant?

David
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