[PATCH 1/2] arm-ccn: ensure perf synchronisation

Mark Rutland mark.rutland at arm.com
Mon Jul 4 06:50:29 PDT 2016


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 at arm.com>
> 
> Acked-by: Pawel Moll <pawel.moll at 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.



More information about the linux-arm-kernel mailing list