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Date: Thu, 21 Jan 2010 11:43:02 +0100
Message-ID: <bd4cb8901001210243y16dbbf8doe66cf24d15120443@mail.gmail.com>
Subject: Re: [PATCH] perf_events: improve x86 event scheduling (v5)
From: Stephane Eranian <eranian@google.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, paulus@samba.org,
       davem@davemloft.net, fweisbec@gmail.com, perfmon2-devel@lists.sf.net,
       eranian@gmail.com
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On Thu, Jan 21, 2010 at 11:36 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, 2010-01-18 at 10:58 +0200, Stephane Eranian wrote:
>>  void hw_perf_enable(void)
>>  {
>
>
>> +               cpuc->n_added = 0;
>> +               perf_events_lapic_init();
>
> Just wondering, why do we need that lapic_init() there?
>
I think I picked it up from x86_pmu_enable(). I don't think
you necessarily need it here. Not clear to me why it was
in x86_pmu_enable() to begin with.

I will post a new version of the patch which fixes some bugs and
also implements true fast path (reuse of previous assignment). It turned
out, things were a bit more complicated than what I had in v5.