Re: [PATCH 2/2] irq: only update affinity in chip set_affinity()

From: Ingo Molnar
Date: Wed Apr 08 2009 - 08:55:45 EST



* Yinghai Lu <yinghai@xxxxxxxxxx> wrote:

> Impact: keep affinity consistent
>
> irq_set_affinity() and move_masked_irq() try to assign affinity
> before calling chip set_affinity(). some archs are assigning again
> in set_affinity again.
>
> something like:
> cpumask_cpy(desc->affinity, mask);
> desc->chip->set_affinity(mask);
>
> in the failing path, affinity should not be touched.
>
> also set_extra_move_desc() ( called by set_affinity) will rely on
> the old affinity to decide if need to move irq_desc to different
> node when logical flat apic mode is used.
>
> So try remove those assignment, and make some missed arch to
> assign affinity in their set_affinity.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> --
> arch/alpha/kernel/sys_dp264.c | 6 ++++--
> arch/alpha/kernel/sys_titan.c | 3 ++-
> arch/arm/common/gic.c | 1 +
> arch/cris/arch-v32/kernel/irq.c | 1 +
> arch/ia64/kernel/iosapic.c | 3 +++
> arch/ia64/sn/kernel/irq.c | 3 +++
> arch/mips/cavium-octeon/octeon-irq.c | 6 ++++++
> arch/mips/sibyte/bcm1480/irq.c | 2 ++
> arch/mips/sibyte/sb1250/irq.c | 2 ++
> arch/powerpc/platforms/pseries/xics.c | 5 +++++
> arch/powerpc/sysdev/mpic.c | 2 ++
> arch/sparc/kernel/irq_64.c | 7 +++++++
> drivers/xen/events.c | 2 ++
> kernel/irq/manage.c | 6 ++----
> kernel/irq/migration.c | 8 +++-----
> 15 files changed, 45 insertions(+), 12 deletions(-)

Hm, this spreads a lot of instances of identical lines:

cpumask_copy(irq_desc[irq].affinity, mask_val);

all around architectures. How is that an improvement?

Ingo
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