Re: [PATCH] arm: fix a migrating irq bug when hotplug cpu

[Linus Walleij]

On Thu, Jan 10, 2019 at 11:09 AM Dietmar Eggemann
<dietmar.eggemann@xxxxxxx> wrote:
>
> Arm TC2 fails cpu hotplug stress test.
>
> This issue was tracked down to a missing copy of the new affinity
> cpumask for the vexpress-spc interrupt into struct
> irq_common_data.affinity when the interrupt is migrated in
> migrate_one_irq().
>
> Fix it by replacing the arm specific hotplug cpu migration with the
> generic irq code.
>
> This is the counterpart implementation to commit 217d453d473c ("arm64:
> fix a migrating irq bug when hotplug cpu").
>
> Tested with cpu hotplug stress test on Arm TC2 (multi_v7_defconfig plus
> CONFIG_ARM_BIG_LITTLE_CPUFREQ=y and CONFIG_ARM_VEXPRESS_SPC_CPUFREQ=y).
> The vexpress-spc interrupt (irq=22) on this board is affine to CPU0.
> Its affinity cpumask now changes correctly e.g. from 0 to 1-4 when
> CPU0 is hotplugged out.
>
> Suggested-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>

Looks solid to me(TM)

I would proceed to put it into Russell's patch tracker along with Marc's
ACK so Russell can process it, see:
http://www.arm.linux.org.uk/developer/patches/

Yours,
Linus Walleij