* [PATCH for-4.8] irq/affinity: use get/put_online_cpus
@ 2016-08-11 14:06 Christoph Hellwig
2016-08-14 16:00 ` Christoph Hellwig
2016-08-22 9:28 ` [tip:irq/urgent] genirq/affinity: Use get/put_online_cpus around cpumask operations tip-bot for Christoph Hellwig
0 siblings, 2 replies; 4+ messages in thread
From: Christoph Hellwig @ 2016-08-11 14:06 UTC (permalink / raw)
To: tglx; +Cc: linux-kernel
Without locking out CPU mask operations we might end up with an inconsistent
view of the cpumask in the function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/irq/affinity.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index f689593..32f6cfc 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -39,6 +39,7 @@ struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
return NULL;
}
+ get_online_cpus();
if (max_vecs >= num_online_cpus()) {
cpumask_copy(affinity_mask, cpu_online_mask);
*nr_vecs = num_online_cpus();
@@ -56,6 +57,7 @@ struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
}
*nr_vecs = vecs;
}
+ put_online_cpus();
return affinity_mask;
}
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH for-4.8] irq/affinity: use get/put_online_cpus
2016-08-11 14:06 [PATCH for-4.8] irq/affinity: use get/put_online_cpus Christoph Hellwig
@ 2016-08-14 16:00 ` Christoph Hellwig
2016-08-22 9:01 ` Thomas Gleixner
2016-08-22 9:28 ` [tip:irq/urgent] genirq/affinity: Use get/put_online_cpus around cpumask operations tip-bot for Christoph Hellwig
1 sibling, 1 reply; 4+ messages in thread
From: Christoph Hellwig @ 2016-08-14 16:00 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: tglx, linux-kernel
Any chance to get a quick review for this and get it off to Linus?
Without this fix the function is unusable in 4.8+ on my test systems
because we seem to always get a inconsistent view of the cpu online
bitmap - something that didn't happen before this merge window oddly
enough.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH for-4.8] irq/affinity: use get/put_online_cpus
2016-08-14 16:00 ` Christoph Hellwig
@ 2016-08-22 9:01 ` Thomas Gleixner
0 siblings, 0 replies; 4+ messages in thread
From: Thomas Gleixner @ 2016-08-22 9:01 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: Christoph Hellwig, linux-kernel
On Sun, 14 Aug 2016, Christoph Hellwig wrote:
> Any chance to get a quick review for this and get it off to Linus?
> Without this fix the function is unusable in 4.8+ on my test systems
> because we seem to always get a inconsistent view of the cpu online
> bitmap - something that didn't happen before this merge window oddly
> enough.
That only happens if you have concurrent cpu hotplug operations, but yes this
needs to be fixed anyway.
Thanks,
tglx
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:irq/urgent] genirq/affinity: Use get/put_online_cpus around cpumask operations
2016-08-11 14:06 [PATCH for-4.8] irq/affinity: use get/put_online_cpus Christoph Hellwig
2016-08-14 16:00 ` Christoph Hellwig
@ 2016-08-22 9:28 ` tip-bot for Christoph Hellwig
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot for Christoph Hellwig @ 2016-08-22 9:28 UTC (permalink / raw)
To: linux-tip-commits; +Cc: tglx, linux-kernel, hpa, hch, mingo
Commit-ID: 3ee0ce2a54dff07d09440723594df89bc1a12e79
Gitweb: http://git.kernel.org/tip/3ee0ce2a54dff07d09440723594df89bc1a12e79
Author: Christoph Hellwig <hch@lst.de>
AuthorDate: Thu, 11 Aug 2016 07:06:45 -0700
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 22 Aug 2016 11:22:44 +0200
genirq/affinity: Use get/put_online_cpus around cpumask operations
Without locking out CPU mask operations we might end up with an inconsistent
view of the cpumask in the function.
Fixes: 5e385a6ef31f: "genirq: Add a helper to spread an affinity mask for MSI/MSI-X vectors"
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/1470924405-25728-1-git-send-email-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/irq/affinity.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index f689593..32f6cfc 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -39,6 +39,7 @@ struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
return NULL;
}
+ get_online_cpus();
if (max_vecs >= num_online_cpus()) {
cpumask_copy(affinity_mask, cpu_online_mask);
*nr_vecs = num_online_cpus();
@@ -56,6 +57,7 @@ struct cpumask *irq_create_affinity_mask(unsigned int *nr_vecs)
}
*nr_vecs = vecs;
}
+ put_online_cpus();
return affinity_mask;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-08-22 9:28 UTC | newest]
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2016-08-11 14:06 [PATCH for-4.8] irq/affinity: use get/put_online_cpus Christoph Hellwig
2016-08-14 16:00 ` Christoph Hellwig
2016-08-22 9:01 ` Thomas Gleixner
2016-08-22 9:28 ` [tip:irq/urgent] genirq/affinity: Use get/put_online_cpus around cpumask operations tip-bot for Christoph Hellwig
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