lkml.org 
[lkml]   [2016]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH RFC 4/5] x86,fpu: lazily skip FPU restore when still loaded
From
Date
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.

--
All rights reversed
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2016-10-03 23:03    [W:0.041 / U:3.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site