Messages in this thread Patch in this message | | | Date | Tue, 24 Mar 2009 21:30:38 GMT | From | Rusty Russell <> | Subject | [tip:x86/apic] x86: Correct behaviour of irq affinity |
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Commit-ID: 85a328f27b927e3f42563c76e1a6992068100433 Gitweb: http://git.kernel.org/tip/85a328f27b927e3f42563c76e1a6992068100433 Author: Rusty Russell <rusty@rustcorp.com.au> AuthorDate: Tue, 24 Mar 2009 14:17:19 -0700 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Tue, 24 Mar 2009 22:28:39 +0100
x86: Correct behaviour of irq affinity
Impact: get correct smp_affinity as user requested
The effect of setting desc->affinity (ie. from userspace via sysfs) has varied over time. In 2.6.27, the 32-bit code anded the value with cpu_online_map, and both 32 and 64-bit did that anding whenever a cpu was unplugged.
2.6.29 consolidated this into one routine (and fixed hotplug) but introduced another variation: anding the affinity with cfg->domain.
We should just set it to what the user said - if possible.
(cpu_mask_to_apicid_and already takes cpu_online_mask into account)
Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <49C94DDF.2010703@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- arch/x86/kernel/apic/io_apic.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 1ed6c06..91476aa 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -594,9 +594,10 @@ set_desc_affinity(struct irq_desc *desc, const struct cpumask *mask) /* check that before desc->addinity get updated */ set_extra_move_desc(desc, mask); - cpumask_and(desc->affinity, cfg->domain, mask); - return apic->cpu_mask_to_apicid_and(desc->affinity, cpu_online_mask); + cpumask_copy(desc->affinity, mask); + + return apic->cpu_mask_to_apicid_and(desc->affinity, cfg->cpu_domain); } static void
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