Re: [rfc] SLOB memory ordering issue

[Linus Torvalds <torvalds@linux-foundation.org>]

On Thu, 16 Oct 2008, Nick Piggin wrote:
> 
> When I said "I'd really hate to add a branch to the slab fastpath", it
> wasn't a tacit acknowlegement that the barrier is the only way to go,
> if it sounded that way.
> 
> I meant: I'd *really* hate to add a branch to the slab fastpath :)

Well, quite frankly, your choice of subject line and whole point of 
argument may have confused me.

You started out - and continue to - make this sound like it's a 
SLAB/SLOB/SLUB issue. It's not. 

I agree there is quite likely memory ordering issues - possibly old ones, 
but quite possibly also ones that have just happened fairly recently as 
we've done more unlocked lookups - and all I've ever disagreed with is 
how you seem to have mixed this up with the allocator.

And I still don't understand why you even _mention_ the slab fastpath. It 
seems totally immaterial.

			Linus

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>