Messages in this thread | | | Date | Mon, 20 Jan 2014 02:19:30 -0800 | From | "H. Peter Anvin" <> | Subject | Re: linux-next: build failure after merge of the tip tree |
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On 01/20/2014 02:13 AM, Peter Zijlstra wrote: > On Mon, Jan 20, 2014 at 09:30:21AM +0100, Peter Zijlstra wrote: >> Then make them so. The fact was that most of the mwait idle sites >> were bloody broken. And the single mwait_idle_with_hints() function >> presents a single nice function that does all the required magics. > > To stress this a bit more; have a look see at mwwait_idle_with_hints(); > it does a whole lot of subtle magic. > > - current_{set,clr}_polling*(), these are crucial in not missing and > wrecking NEED_RESCHED state. > > - X86_FEATURE_CLFLUSH_MONTIOR quirk > > - Does the monitor(); if (!need_resched()) mwait() thing. > > All of those are required for a correct and functional idle loop. And > I've seen sites where any or all of the above were missing/broken. > > Not unifying the lot into a simple usable function is just stupid -- > history has shown people simply cannot be trusted to get this right. >
I don't think anyone is arguing that. The question is rather if the implementation is correct, and if it is ready for the merge window.
-hpa
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