Re: [PATCH]: arm64: factor work_pending state machine to C

From: Will Deacon
Date: Mon Jul 11 2016 - 07:42:53 EST


On Fri, Jul 08, 2016 at 04:49:01PM +0100, Will Deacon wrote:
> On Fri, Jul 08, 2016 at 11:43:50AM -0400, Chris Metcalf wrote:
> > I am hopeful that this patch [1] can be picked up for the 4.8 merge window
> > in the arm64 tree. As I mentioned in my last patch series that included
> > this patch [2], I'm hopeful that this version addresses the performance
> > issues that were seen with Mark's original patch. This version tests the
> > TIF flags prior to calling out to the loop in C code.
>
> I still need to get round to measuring that again. This might also
> conflict with a late fix I just sent for 4.7.

FWIW, I've failed to measure any performance overhead from this change,
so it certainly looks better thsn Mark's original patch from that angle.

Will