Messages in this thread | | | Date | Wed, 7 Dec 2011 01:48:30 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [RFC] genirq: Flush the irq thread on synchronization |
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On Wed, 7 Dec 2011, Ido Yariv wrote:
> Hi Thomas, > > On Mon, Dec 05, 2011 at 10:55:01PM +0100, Thomas Gleixner wrote: > > Does the following (untested) patch solve your issues? > > I briefly tested this patch and it appears to also solve the issues I > mentioned. > > I think both solutions would work. The only drawbacks I see in using > this patch over the other one are that this patch involves a bit more > locking in synchronize_irq() and irq_finalize_oneshot() (for non-oneshot > irqs), and that the oneshot mechanism is used for non-oneshot threads.
I don't care about synchronize_irq() at all. It's a slow path anyway.
The extra burden in irq_finalize_oneshot() is somewhat of a concern, but that locks should be completely uncontended for real threaded irq users, so in practice it's a non issue.
It's the only solution which actually solves the thread_active leak, though I just discovered a very narrow race window between the test_and_clear_bit and the active increment, which is easy to fix. I'll send out another version tomorrow
Thanks,
tglx
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