diff options
| author | Pallipadi, Venkatesh <venkatesh.pallipadi@intel.com> | 2009-04-13 15:20:58 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-14 15:21:13 +0200 |
| commit | 6ec3cfeca04622e3d80c9270191cd7f5f88214af (patch) | |
| tree | ba9d66ec365e59842fe97d72855c6065763dfe98 /kernel | |
| parent | b21597d0268983f8f9e8b563494f75490403e948 (diff) | |
| download | linux-6ec3cfeca04622e3d80c9270191cd7f5f88214af.tar.bz2 | |
x86, irq: Remove IRQ_DISABLED check in process context IRQ move
As discussed in the thread here:
http://marc.info/?l=linux-kernel&m=123964468521142&w=2
Eric W. Biederman observed:
> It looks like some additional bugs have slipped in since last I looked.
>
> set_irq_affinity does this:
> ifdef CONFIG_GENERIC_PENDING_IRQ
> if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
> cpumask_copy(desc->affinity, cpumask);
> desc->chip->set_affinity(irq, cpumask);
> } else {
> desc->status |= IRQ_MOVE_PENDING;
> cpumask_copy(desc->pending_mask, cpumask);
> }
> #else
>
> That IRQ_DISABLED case is a software state and as such it has nothing to
> do with how safe it is to move an irq in process context.
[...]
>
> The only reason we migrate MSIs in interrupt context today is that there
> wasn't infrastructure for support migration both in interrupt context
> and outside of it.
Yes. The idea here was to force the MSI migration to happen in process
context. One of the patches in the series did
disable_irq(dev->irq);
irq_set_affinity(dev->irq, cpumask_of(dev->cpu));
enable_irq(dev->irq);
with the above patch adding irq/manage code check for interrupt disabled
and moving the interrupt in process context.
IIRC, there was no IRQ_MOVE_PCNTXT when we were developing this HPET
code and we ended up having this ugly hack. IRQ_MOVE_PCNTXT was there
when we eventually submitted the patch upstream. But, looks like I did a
blind rebasing instead of using IRQ_MOVE_PCNTXT in hpet MSI code.
Below patch fixes this. i.e., revert commit 932775a4ab622e3c99bd59f14cc
and add PCNTXT to HPET MSI setup. Also removes copying of desc->affinity
in generic code as set_affinity routines are doing it internally.
Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Li Shaohua" <shaohua.li@intel.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: "lcm@us.ibm.com" <lcm@us.ibm.com>
Cc: suresh.b.siddha@intel.com
LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/irq/manage.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 7e2e7dd4cd2f..2734eca59243 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -109,10 +109,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) spin_lock_irqsave(&desc->lock, flags); #ifdef CONFIG_GENERIC_PENDING_IRQ - if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { - cpumask_copy(desc->affinity, cpumask); + if (desc->status & IRQ_MOVE_PCNTXT) desc->chip->set_affinity(irq, cpumask); - } else { + else { desc->status |= IRQ_MOVE_PENDING; cpumask_copy(desc->pending_mask, cpumask); } |