Messages in this thread |  | | Subject | Re: [PATCH RFC 4/5] x86,fpu: lazily skip FPU restore when still loaded | From | Rik van Riel <> | Date | Mon, 03 Oct 2016 17:02:57 -0400 |
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On Mon, 2016-10-03 at 13:49 -0700, Dave Hansen wrote: > On 10/03/2016 01:22 PM, Rik van Riel wrote: > > > > > > > > > > > > > What are the preempt rules with this thing? This needs to be > > > > called > > > > in preempt-disabled contexts, right? > > Indeed, all the FPU context switching code needs > > to be called in preempt-disabled contexts. > > > > You do not want to get preempted halfway through > > saving or restoring floating point registers. > OK, cool, that's what I expected. Could you just add a comment about > it > to make it clear that it's also the case for this new > fpu_lazy_skip_restore() helper?
Turns out the code already has an old fpu_want_lazy_restore(), which is what I will use instead :)
I will add documentation about preemption in places where it is necessary.
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