From: Baoquan He <bhe@redhat.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Stable tree <stable@vger.kernel.org>
Subject: Re: [PATCH] mm, memory_hotplug: teach has_unmovable_pages about of LRU migrateable pages
Date: Tue, 6 Nov 2018 17:36:45 +0800 [thread overview]
Message-ID: <20181106093645.GM27491@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20181106091624.GL27491@MiWiFi-R3L-srv>
On 11/06/18 at 05:16pm, Baoquan He wrote:
> On 11/06/18 at 09:28am, Michal Hocko wrote:
> > > > > > > It failed. Paste the log and patch diff here, please help check if I made
> > > > > > > any mistake on manual code change. The log is at bottom.
> > > > > >
> > > > > > The retry patch is obviously still racy, it just makes the race window
> > > > > > slightly smaller and I hoped it would catch most of those races but this
> > > > > > is obviously not the case.
> > > > > >
> > > > > > I was thinking about your MIGRATE_MOVABLE check some more and I still do
> > > > > > not like it much, we just change migrate type at many places and I have
> > > > > > hard time to actually see this is always safe wrt. to what we need here.
> > > > > >
> > > > > > We should be able to restore the zone type check though. The
> > > > > > primary problem fixed by 15c30bc09085 ("mm, memory_hotplug: make
> > > > > > has_unmovable_pages more robust") was that early allocations made it to
> > > > > > the zone_movable range. If we add the check _after_ the PageReserved()
> > > > > > check then we should be able to rule all bootmem allocation out.
> > > > > >
> > > > > > So what about the following (on top of the previous patch which makes
> > > > > > sense on its own I believe).
> > > > >
> > > > > Yes, I think this looks very reasonable and should be robust.
> > > > >
> > > > > Have tested it, hot removing 4 hotpluggable nodes continusously
> > > > > succeeds, and then hot adding them back, still works well.
> > > > >
> > > > > So please feel free to add my Tested-by or Acked-by.
> > > > >
> > > > > Tested-by: Baoquan He <bhe@redhat.com>
> > > > > or
> > > > > Acked-by: Baoquan He <bhe@redhat.com>
> > > >
> > > > Thanks for retesting! Does this apply to both patches?
> > >
> > > Sorry, don't get it. I just applied this on top of linus's tree and
> > > tested. Do you mean applying it on top of previous code change?
> >
> > Yes. While the first patch will obviously not help for movable zone
> > because the movable check will override any later check it
> > seems still useful to reduce false positives on normal zones.
>
> Hmm, I don't know if it will bring a little bit confusion on code
> understanding. Since we only recognize the movable zone issue, and I can
> only reproduce and verify it on the movable zone issue with the movable
> zone check adding.
>
> Not sure if there are any scenario or use cases to cover those newly added
> checking other movable zone checking. Surely, I have no objection to
^ than
> adding them. But the two patches are separate issues, they have no
> dependency on each other.
>
> I just tested the movable zone checking yesterday, will add your
> previous check back, then test again. I believe the result will be
> positive. Will udpate once done.
>
> Thanks
> Baoquan
next prev parent reply other threads:[~2018-11-06 9:36 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-01 9:10 Memory hotplug failed to offline on bare metal system of multiple nodes Baoquan He
2018-11-01 9:22 ` Michal Hocko
2018-11-01 9:42 ` Baoquan He
2018-11-01 9:58 ` Michal Hocko
2018-11-02 15:55 ` [PATCH] mm, memory_hotplug: teach has_unmovable_pages about of LRU migrateable pages Michal Hocko
2018-11-05 0:20 ` Baoquan He
2018-11-05 9:14 ` Michal Hocko
2018-11-05 9:26 ` Baoquan He
2018-11-05 9:35 ` Michal Hocko
2018-11-05 9:28 ` Michal Hocko
2018-11-05 9:45 ` Baoquan He
2018-11-05 10:25 ` Baoquan He
2018-11-05 12:38 ` Michal Hocko
2018-11-05 14:23 ` Baoquan He
2018-11-05 17:10 ` Michal Hocko
2018-11-06 0:22 ` Baoquan He
2018-11-06 8:28 ` Michal Hocko
2018-11-06 9:16 ` Baoquan He
2018-11-06 9:36 ` Baoquan He [this message]
2018-11-06 9:51 ` Michal Hocko
2018-11-06 10:00 ` Baoquan He
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181106093645.GM27491@MiWiFi-R3L-srv \
--to=bhe@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).