Messages in this thread | | | Date | Wed, 13 Aug 2008 10:25:04 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] kexec jump: fix compiling warning on xchg(&kexec_lock, 0) in kernel_kexec() |
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On Wed, 13 Aug 2008 10:01:13 -0700 (PDT) Linus Torvalds <torvalds@linux-foundation.org> wrote:
> > > On Wed, 13 Aug 2008, Andrew Morton wrote: > > > > We don't need to create that local. I queued this: > > No, please don't. > > Just don't take this whole patch-series until it's cleaned up.
We already took it - in 2.6.13!
> There is > absolutely no excuse for using xchg as a locking primitive. Nothing like > this should be queued anywhere, it should be burned and the ashes should > be scattered over the atlantic so that nobody will ever see them again. > > F*ck me with a spoon, if you have to use xchg() to do a trylock, why the > hell isn't the unlock sequence then > > smp_mb(); > var = 0; > > instead? Not that that's really right either, but at least it avoids the > _ridiculous_ crap. The real solution is probably to use a spinlock and > trylock/unlock. >
Or test_and_set_bit(). That's what I've been saying too, only differently ;)
But cleaning up the long-standing silly usage of xchg() is a different activity from suppressing this recently-added compile warning.
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