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From: Michael Ellerman <michael@ellerman.id.au>
To: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: linuxppc-dev@ozlabs.org, mikey@neuling.org
Subject: Re: [PATCH] powerpc, perf: Configure BHRB filter before enabling PMU interrupts
Date: Tue, 8 Oct 2013 15:21:37 +1100	[thread overview]
Message-ID: <20131008042137.GE31666@concordia> (raw)
In-Reply-To: <1381120226-14838-1-git-send-email-khandual@linux.vnet.ibm.com>

On Mon, Oct 07, 2013 at 10:00:26AM +0530, Anshuman Khandual wrote:
> Right now the `config_bhrb` PMU specific call happens after write_mmcr0
> which actually enables the PMU for event counting and interrupt. So
> there is a small window of time where the PMU and BHRB runs without the
> required HW branch filter (if any) enabled in BHRB. This can cause some
> of the branch samples to be collected through BHRB without any filter
> being applied and hence affecting the correctness of the results. This
> patch moves the BHRB config function call before enabling the interrupts.

Patch looks good.

But it reminds me I have an item in my TODO list:
 - "Why can't config_bhrb() be done in compute_mmcr()" ?

cheers

  reply	other threads:[~2013-10-08  4:21 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-07  4:30 [PATCH] powerpc, perf: Configure BHRB filter before enabling PMU interrupts Anshuman Khandual
2013-10-08  4:21 ` Michael Ellerman [this message]
2013-10-08  7:21   ` Anshuman Khandual
2013-10-09  1:21     ` Michael Ellerman
2013-10-09  4:46       ` Anshuman Khandual
2013-10-09  6:03         ` Michael Ellerman
2013-10-10  8:50           ` Anshuman Khandual
2013-10-11  2:11             ` Michael Ellerman
2013-10-11  4:32               ` Anshuman Khandual
2013-10-14  6:19                 ` Michael Ellerman
2013-10-16  4:30                   ` Anshuman Khandual
2013-12-13  6:46                     ` Anshuman Khandual
  -- strict thread matches above, loose matches on Subject: below --
2013-12-18  2:14 Michael Ellerman
2013-12-18  3:41 ` Anshuman Khandual

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