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Subject: Re: call_function_many: fix list delete vs add race
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
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Date: Tue, 01 Feb 2011 17:16:01 +1100
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On Tue, 2011-02-01 at 12:43 +1000, Linus Torvalds wrote:
> On Tue, Feb 1, 2011 at 12:18 PM, Paul E. McKenney
> <paulmck@linux.vnet.ibm.com> wrote:
> >
> > Documentation/memory-barriers.txt specifies this.
> 
> Good, so it really is documented, with both cases explicitly mentioned.
> 
> That said, I do think that if your memory ordering is much weaker than
> x86, you are going to see bugs that most testers don't see, and it
> simply might not be worth it.

Allright. The way we do it on power is stores won't pass the unlock
either way (lwsync). Some loads might migrate up tho.

Cheers,
Ben.