Re: [PATCH v9 00/13] support "task_isolation" mode for nohz_full

[Chris Metcalf]

On 01/13/2016 05:44 AM, Ingo Molnar wrote:
> * Chris Metcalf <cmetcalf@xxxxxxxxxx> wrote:
>
> > (Adding Mark to cc's)
> >
> > On 01/12/2016 05:07 AM, Will Deacon wrote:
> > > On Mon, Jan 11, 2016 at 04:15:50PM -0500, Chris Metcalf wrote:
> > > > Ping!  There has been no substantive feedback to this version of
> > > > the patch in the week since I posted it, which optimistically suggests
> > > > to me that people may be satisfied with it.  If that's true, Frederic,
> > > > I assume this would be pulled into your tree?
> > > >
> > > > I have slightly updated the v9 patch series since this posting:
> > > >
> > > > [...]
> > > >
> > > > - Incorporated Mark Rutland's changes to convert arm64
> > > >    assembly to C code instead of using my own version.
> > > Please avoid queuing these patches -- the first is already in the arm64
> > > queue for 4.5 and the second was found to introduce a substantial
> > > performance regression on the syscall entry/exit path. I think Mark had
> > > an updated version to address that, so it would be easier not to have
> > > an old version sitting in some other queue!
> > I am not formally queueing them anywhere (like linux-next), though
> > now that you mention it, that's a pretty good idea - I'll talk to Steven
> > about that, assuming this merge window closes without the task
> > isolation stuff going in.
> NAK. Given the controversy, no way should this stuff go outside the primary trees
> it affects: the scheduler, timer, irq, etc. trees.

Fair enough.  I'll plan to do v10 once the merge window closes.

Mark, let me know when/if you get a new version of the de-asm stuff
for do_notify_resume() - thanks.  Or, would it be helpful if I worked up
the option I suggested, where we check the thread_info flags in the
assembly code before calling out to the new loop in do_notify_resume()?

--
Chris Metcalf, EZChip Semiconductor
http://www.ezchip.com