Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 27 Feb 2019 09:38:04 -0800 | Subject | Re: [PATCH 1/5] x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() |
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On Wed, Feb 27, 2019 at 9:34 AM Peter Zijlstra <peterz@infradead.org> wrote: > > But the ONCE thing defeats CSE (on purpose!) so for code-gen that > likes/wants that we then have to use the __this_cpu crud.
Right. But I do think that if you want CSE on a percpu access, you might want to write it as such (ie load the value once and then re-use the value).
But I'm not sure exactly which accesses Nadav noticed to be a problem, so.. I guess I should just look at the other patches, but I found them rather nasty and ad-hoc too so I just skimmed them with an "eww" ;)
Linus
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