Re: [PATCH 0/3] Reduce amount of time kswapd sleeps prematurely

[Andrew Morton]

On Wed, 15 Feb 2017 21:29:06 +0000 Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> wrote:

> On Wed, Feb 15, 2017 at 12:30:55PM -0800, Andrew Morton wrote:
> > On Wed, 15 Feb 2017 09:22:44 +0000 Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> wrote:
> > 
> > > This patchset is based on mmots as of Feb 9th, 2016. The baseline is
> > > important as there are a number of kswapd-related fixes in that tree and
> > > a comparison against v4.10-rc7 would be almost meaningless as a result.
> > 
> > It's very late to squeeze this into 4.10.  We can make it 4.11 material
> > and perhaps tag it for backporting into 4.10.1?
> 
> It would be important that Johannes's patches go along with then because
> I'm relied on Johannes' fixes to deal with pages being inappropriately
> written back from reclaim context when I was analysing the workload.
> I'm thinking specifically about these patches
> 
> mm-vmscan-scan-dirty-pages-even-in-laptop-mode.patch
> mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru.patch
> mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch
> mm-vmscan-remove-old-flusher-wakeup-from-direct-reclaim-path.patch
> mm-vmscan-only-write-dirty-pages-that-the-scanner-has-seen-twice.patch
> mm-vmscan-move-dirty-pages-out-of-the-way-until-theyre-flushed.patch
> mm-vmscan-move-dirty-pages-out-of-the-way-until-theyre-flushed-fix.patch
> 
> This is 4.11 material for sure but I would not automatically try merging
> them to 4.10 unless those patches were also included, ideally with a rerun
> of just those patches against 4.10 to make sure there are no surprises
> lurking in there.

Head spinning a bit.  You're saying that if the three patches in the
series "Reduce amount of time kswapd sleeps prematurely" are held off
until 4.11 then the above 6 patches from Johannes should also be held
off for 4.11?