Messages in this thread | | | Subject | Re: RCU stall in af_unix.c, should use spin_lock_irqsave? | From | Eric Dumazet <> | Date | Tue, 21 Oct 2014 03:28:20 -0700 |
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On Tue, 2014-10-21 at 12:10 +0200, Thomas Petazzoni wrote:
> Ok. So it's actually safe to mix spin_lock() and spin_lock_irqsave() on > the same lock, if you know that this lock will never ever be taken in > an interrupt context?
Sure.
> > > mvpp2 is seriously brain damaged : on_each_cpu() cannot be used from > > a bottom half handler. > > That's what I thought. Back to the drawing board then, to fix mvpp2. > > Do you think there is a place where we can write down those > assumptions? It isn't easy to spot whether on_each_cpu() is safe to use > in a bottom half or not. >
Really ? kernel/smp.c is full of comments.
Too many comments and people seem to not read them ;)
Take a look at smp_call_function(), which is called from on_each_cpu()
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