Re: [patch] x86: improved memory barrier implementation

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From: Alan Cox
Date: Friday, September 28, 2007 - 10:18 am

> on the broken ppro stores config option if you just tell me what should

The PPro needs rmb to ensure a store doesn't go for a walk on the wild
side and pass the read especially when we are dealing with device space.
The rest of the stuff is a little vague which makes me nervous when
considering relaxing the PPro case for smp_rmb. With smp_rmb as it is at
the moment the PPro is effectively treated as an out of order cpu and so
shouldn't hit anything occassionally that a PPC wouldn't hit every time.


Well Linus has dealt with the question of NT stores for us now...

Given this isn't an issue on 64bit I'm inclined to argue that only 64bit
behaviour should be changed at this point.

Alan
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Messages in current thread:
[patch] x86: improved memory barrier implementation, Nick Piggin, (Fri Sep 28, 8:48 am)
Re: [patch] x86: improved memory barrier implementation, Linus Torvalds, (Fri Sep 28, 9:15 am)
Re: [patch] x86: improved memory barrier implementation, Alan Cox, (Fri Sep 28, 10:18 am)
Re: [patch] x86: improved memory barrier implementation, Linus Torvalds, (Sat Sep 29, 9:07 am)