Messages in this thread | | | Date | Mon, 20 Jan 2014 09:26:20 +0100 | From | Peter Zijlstra <> | Subject | Re: linux-next: build failure after merge of the tip tree |
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On Sun, Jan 19, 2014 at 11:45:43PM -0500, Len Brown wrote: > +static void mwait_idle(void) > +{ > + mwait_idle_with_hints(0, 0); > +} > + > > The reason the patch above will crash Core2 machines is because > core2 machines don't support mwait_idle_with_hints(). > > The calling sequence for old and new MWAIT instructions is different. > The former must be invoked with interrupts enabled, > and the later can be invoked with interrupts disabled, > which is a feature that Linux takes advantage of.
What old and new? They're the same byte sequence: 0x0f 0x01 0xc9
And your 'old' __sti_mwait(0,0) has the exact same arguments as mwait_idle_with_hints(0,0).
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