AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

x86: Correct behaviour of irq affinity

Browse Source 
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>
This commit is contained in:
Rusty Russell 2009-03-24 14:17:19 -07:00 committed by Ingo Molnar
parent f56e503412
commit e06b1b56f9
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/x86/kernel/apic/io_apic.c
View File

@ -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->domain);
}
static void