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	<20150211113946.GT23123@twins.programming.kicks-ass.net>
Date: Wed, 11 Feb 2015 08:18:37 -0500
Message-ID: <CABPqkBR-mg00JS5KF+9oGg=+Xo+eprYSk5WYEg0P2w30JGXCoQ@mail.gmail.com>
Subject: Re: [PATCH 0/4] perf: add support for profiling jitted code
From: Stephane Eranian <eranian@google.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        "mingo@elte.hu" <mingo@elte.hu>,
        "ak@linux.intel.com" <ak@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
        Rose Belcher <cel@us.ibm.com>,
        Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>,
        Sonny Rao <sonnyrao@chromium.org>,
        John Mccutchan <johnmccutchan@google.com>,
        David Ahern <dsahern@gmail.com>
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Peter,

On Wed, Feb 11, 2015 at 6:39 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Feb 11, 2015 at 12:42:41AM +0100, Stephane Eranian wrote:
>> To enable synchronization of the runtime MMAPs with those recorded by
>> the kernel on behalf of the perf tool, the runtime needs to timestamp
>> any record in the dump file using the same time source. The current
>> patch series is relying on Sonny Rao's posix-clock patch series
>> posted on LKML in 2013. The link to the patches is:
>>       https://lkml.org/lkml/2013/12/6/1044
>>
>
> At least for x86 you could use something like this:
>
>   lkml.kernel.org/r/aa2dd2e4f1e9f2225758be5ba00f14d6909a8ce1.1423180257.git.shli@fb.com
>
> We can re-create the perf_clock() from the tsc with the mult, shift and
> offset provided in the perf userpage.

I had forgotten that I had modified Sonny's patch to use sched_clock(). I will
post V2 using David Ahern's driver instead.

But, we need a portable solution, there are jitted environment on other
architectures.
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