Messages in this thread | | | Date | Wed, 08 Mar 2006 19:52:17 +1100 | From | Nick Piggin <> | Subject | Re: [patch] i386 spinlocks: disable interrupts only if we enabled them |
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Andrew Morton wrote: > Benjamin LaHaise <bcrl@kvack.org> wrote: > >>On Wed, Mar 08, 2006 at 01:43:08AM +0100, Ingo Molnar wrote: >> > we dont inline that code anymore. So i think the optimization is fine. >> >> Why is that? It adds memory traffic that has to be synchronized >> before the lock occurs and clobbered registers now in the caller. > > > Is the inlined lock;decb+jns likely to worsen the text size? I doubt it. > Overall text will get bigger due to the out-of-line stuff, but that's OK. > > I'm sure we went over all this, but I don't recall the thinking.
Seems like a very good idea not to clobber any registers in lock fastpaths. I don't see how that could have been a win (especially for i386) but still, Ingo must have had a reason behind it.
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