Messages in this thread | | | Date | Tue, 7 Mar 2023 21:43:30 +0100 | From | Jakub Jelinek <> | Subject | Re: [PATCH] x86/resctrl: avoid compiler optimization in __resctrl_sched_in |
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On Tue, Mar 07, 2023 at 12:43:16PM -0600, Segher Boessenkool wrote: > On Tue, Mar 07, 2023 at 12:35:45PM +0100, Peter Zijlstra wrote: > > So per that summary, I'm going to nit-pick and state we very much want > > CSE. CSE good. What we don't want it violating store-load ordering. > > So you need to describe exactly what you *do* want. There is no way to > forbid most otherwise valid things. But you can express pretty much all > dependencies. > > > Oh, geez, what a twisty tale that... So Linus knew back in '09 that "p" > > was icky, but it sorta was the only thing and it 'worked' -- until now > > :/ > > The "p" constraint is just like any other address_constraint, in most > aspects. Since this is very specific to "p", that limits what is going > on to really just one thing.
Are we actually talking here about "p" constraint or about p/P (x86) modifiers (asm ("%p0" : : "i" (42));)?
Jakub
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