[tip:x86/irq] x86: Eliminate pointless adjustment attempts in fixup_irqs()

From: tip-bot for Jan Beulich
Date: Fri Feb 18 2011 - 05:41:26 EST


Commit-ID: 58bff947e2d164c7e5cbf7f485e4b3d4884befeb
Gitweb: http://git.kernel.org/tip/58bff947e2d164c7e5cbf7f485e4b3d4884befeb
Author: Jan Beulich <JBeulich@xxxxxxxxxx>
AuthorDate: Thu, 17 Feb 2011 15:54:26 +0000
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 18 Feb 2011 08:58:00 +0100

x86: Eliminate pointless adjustment attempts in fixup_irqs()

Not only when an IRQ's affinity equals cpu_online_mask is there
no need to actually try to adjust the affinity, but also when
it's a subset thereof. This particularly avoids adjustment
attempts during system shutdown to any IRQs bound to CPU#0.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: Gary Hade <garyhade@xxxxxxxxxx>
LKML-Reference: <4D5D52C2020000780003272C@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/irq.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 387b6a0..78793ef 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -310,7 +310,7 @@ void fixup_irqs(void)
data = &desc->irq_data;
affinity = data->affinity;
if (!irq_has_action(irq) ||
- cpumask_equal(affinity, cpu_online_mask)) {
+ cpumask_subset(affinity, cpu_online_mask)) {
raw_spin_unlock(&desc->lock);
continue;
}
--
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