Messages in this thread | | | Date | Wed, 22 Jun 2016 10:07:18 +0900 | From | Joonsoo Kim <> | Subject | Re: + mm-compaction-split-freepages-without-holding-the-zone-lock-fix.patch added to -mm tree |
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On Tue, Jun 21, 2016 at 05:53:22PM -0700, David Rientjes wrote: > On Wed, 22 Jun 2016, Joonsoo Kim wrote: > > > On Tue, Jun 21, 2016 at 04:14:28PM -0700, akpm@linux-foundation.org wrote: > > > > > > The patch titled > > > Subject: mm/compaction: split freepages without holding the zone lock fix > > > has been added to the -mm tree. Its filename is > > > mm-compaction-split-freepages-without-holding-the-zone-lock-fix.patch > > > > > > This patch should soon appear at > > > http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-split-freepages-without-holding-the-zone-lock-fix.patch > > > and later at > > > http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-split-freepages-without-holding-the-zone-lock-fix.patch > > > > > > Before you just go and hit "reply", please: > > > a) Consider who else should be cc'ed > > > b) Prefer to cc a suitable mailing list as well > > > c) Ideally: find the original patch on the mailing list and do a > > > reply-to-all to that, adding suitable additional cc's > > > > > > *** Remember to use Documentation/SubmitChecklist when testing your code *** > > > > > > The -mm tree is included into linux-next and is updated > > > there every 3-4 working days > > > > > > ------------------------------------------------------ > > > From: David Rientjes <rientjes@google.com> > > > Subject: mm/compaction: split freepages without holding the zone lock fix > > > > > > If __isolate_free_page() fails, avoid adding to freelist so we don't call > > > map_pages() with it. > > > > > > Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1606211447001.43430@chino.kir.corp.google.com > > > > I've sent the fix already. I don't care which patch is merged but I guess > > below series would be merged more cleanly? It's up to Andrew. > > > > Link: http://lkml.kernel.org/r/1466150259-27727-1-git-send-email-iamjoonsoo.kim@lge.com > > > > Well, http://marc.info/?l=linux-mm&m=146654572331344 fixes an issue that > persists at least as far back as 3.11 whereas we can scan entire 256GB+ > zones needlessly each time compaction_alloc() is called, and that function > can be called multiple times for a single page isolated for migration in > the case of -EAGAIN. It's been measured that compaction_alloc() can take > 15-20% of cpu cycles while faulting thp on very large machines back in the > 3.11 kernel. I would suggest that this is an important fix that needs to > be included and perhaps backported to stable.
Agreed.
> > I don't know the relative importance the reducing the size of page_owner > patchset. It appears that the link you provided is a refreshed series of > a patchset that is already in -mm? If so, I think the old set should be > reverted, and whatever dependencies it has, and then a third version of > http://marc.info/?l=linux-mm&m=146654572331344 merged. I can propose that > for inclusion in this release cycle if folks agree that it's warranted. > > The alternative seems to be to rebase your refreshed series on top of -mm > with the fix.
I think that page_owner patch is less important. Andrew, could you revert whole series? I will refresh series on top of -mm with the David's fix.
Thanks.
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