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From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] arm-ccn: ensure perf synchronisation
Date: Mon, 4 Jul 2016 14:50:29 +0100	[thread overview]
Message-ID: <20160704135029.GB9048@leverpostej> (raw)
In-Reply-To: <1467639584.22236.1.camel@arm.com>

On Mon, Jul 04, 2016 at 02:39:44PM +0100, Pawel Moll wrote:
> Dnia 2016-06-28, Tue o godzinie 18:50 +0100, Mark Rutland pisze:
> > Currently the IRQ core is permitted to make the CCN PMU IRQ handler
> > threaded, and will allow userspace to change the CPU affinity of the
> > interrupt behind our back. Both of these could violate our
> > synchronisation requirements with the core perf code, which relies upon
> > strict CPU affinity and disabling of interrupts to guarantee mutual
> > exclusion in some cases.
> > 
> > As with the CPU PMU drivers, we should request the interrupt with
> > IRQF_NOBALANCING and IRQF_NO_THREAD, to avoid these issues.
> 
> > Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> 
> Acked-by: Pawel Moll <pawel.moll@arm.com>

Cheers. I've just sent v2, so I've applied that locally, and it'll
appear if a v3 is necessary.

> In principle, because still had no chance to test it...

Understood.

Thanks,
Mark.

  reply	other threads:[~2016-07-04 13:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-28 17:50 [PATCH 0/2] arm-cc*: ensure perf synchronisation Mark Rutland
2016-06-28 17:50 ` [PATCH 1/2] arm-ccn: " Mark Rutland
2016-07-04 13:39   ` Pawel Moll
2016-07-04 13:50     ` Mark Rutland [this message]
2016-06-28 17:50 ` [PATCH 2/2] arm-cci: " Mark Rutland
2016-07-04 10:22   ` Will Deacon
2016-07-04 10:31     ` Mark Rutland
2016-07-04 10:44       ` Mark Rutland
2016-07-04 11:16       ` Punit Agrawal

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