From: Michael Ellerman <mpe@ellerman.id.au>
To: Michal Hocko <mhocko@kernel.org>, linux-mm@kvack.org
Cc: Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Reza Arbab <arbab@linux.vnet.ibm.com>,
Yasuaki Ishimatsu <yasu.isimatu@gmail.com>,
qiuxishi@huawei.com, Igor Mammedov <imammedo@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages
Date: Tue, 17 Oct 2017 22:41:08 +1100 [thread overview]
Message-ID: <871sm2j92j.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20171013120013.698-1-mhocko@kernel.org>
Michal Hocko <mhocko@kernel.org> writes:
> From: Michal Hocko <mhocko@suse.com>
>
> Michael has noticed that the memory offline tries to migrate kernel code
> pages when doing
> echo 0 > /sys/devices/system/memory/memory0/online
>
> The current implementation will fail the operation after several failed
> page migration attempts but we shouldn't even attempt to migrate
> that memory and fail right away because this memory is clearly not
> migrateable. This will become a real problem when we drop the retry loop
> counter resp. timeout.
>
> The real problem is in has_unmovable_pages in fact. We should fail if
> there are any non migrateable pages in the area. In orther to guarantee
> that remove the migrate type checks because MIGRATE_MOVABLE is not
> guaranteed to contain only migrateable pages. It is merely a heuristic.
> Similarly MIGRATE_CMA does guarantee that the page allocator doesn't
> allocate any non-migrateable pages from the block but CMA allocations
> themselves are unlikely to migrateable. Therefore remove both checks.
>
> Reported-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
Thanks, that works for me.
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
cheers
next prev parent reply other threads:[~2017-10-17 11:41 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-18 7:08 [PATCH v2 0/2] mm, memory_hotplug: redefine memory offline retry logic Michal Hocko
2017-09-18 7:08 ` [PATCH 1/2] mm, memory_hotplug: do not fail offlining too early Michal Hocko
2017-10-10 12:05 ` Michael Ellerman
2017-10-10 12:27 ` Michal Hocko
2017-10-11 2:37 ` Michael Ellerman
2017-10-11 5:19 ` Michael Ellerman
2017-10-11 14:05 ` Anshuman Khandual
2017-10-11 14:16 ` Michal Hocko
2017-10-11 6:51 ` Michal Hocko
2017-10-11 8:04 ` Vlastimil Babka
2017-10-11 8:13 ` Michal Hocko
2017-10-11 11:17 ` Vlastimil Babka
2017-10-11 11:24 ` Michal Hocko
2017-10-13 11:42 ` Michael Ellerman
2017-10-13 11:58 ` Michal Hocko
2017-10-13 12:00 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michal Hocko
2017-10-13 12:00 ` [PATCH 2/2] mm, page_alloc: fail has_unmovable_pages when seeing reserved pages Michal Hocko
2017-10-13 12:04 ` Vlastimil Babka
2017-10-13 12:07 ` Michal Hocko
2017-10-17 13:03 ` Vlastimil Babka
2017-10-17 11:41 ` Michael Ellerman [this message]
2017-10-17 12:03 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Michal Hocko
2017-10-17 13:02 ` Vlastimil Babka
2017-10-19 2:51 ` Joonsoo Kim
2017-10-19 7:15 ` Michal Hocko
2017-10-19 7:33 ` Joonsoo Kim
2017-10-19 8:20 ` Michal Hocko
2017-10-19 12:21 ` Michal Hocko
2017-10-20 2:13 ` Joonsoo Kim
2017-10-20 5:59 ` Michal Hocko
2017-10-20 6:50 ` Joonsoo Kim
2017-10-20 7:02 ` Michal Hocko
2017-10-23 5:23 ` Joonsoo Kim
2017-10-23 8:10 ` Michal Hocko
2017-10-24 4:44 ` Joonsoo Kim
2017-10-24 7:44 ` Michal Hocko
2017-10-24 8:12 ` Vlastimil Babka
2017-10-24 12:25 ` Michal Hocko
2017-10-26 2:47 ` Joonsoo Kim
2017-10-26 7:41 ` Michal Hocko
2017-10-20 7:22 ` Xishi Qiu
2017-10-20 8:17 ` Michal Hocko
2017-10-23 5:26 ` Joonsoo Kim
2017-10-26 13:04 ` Vlastimil Babka
2017-10-26 13:59 ` Michal Hocko
2017-09-18 7:08 ` [PATCH 2/2] mm, memory_hotplug: remove timeout from __offline_memory Michal Hocko
[not found] <AM3PR04MB14892A9D6D2FBCE21B8C1F0FF12B0@AM3PR04MB1489.eurprd04.prod.outlook.com>
2017-11-13 7:33 ` [PATCH 1/2] mm: drop migrate type checks from has_unmovable_pages Ran Wang
2017-11-13 11:02 ` Michal Hocko
2017-11-14 6:10 ` Ran Wang
2017-11-14 7:06 ` Michal Hocko
2017-11-14 7:45 ` Ran Wang
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=871sm2j92j.fsf@concordia.ellerman.id.au \
--to=mpe@ellerman.id.au \
--cc=akpm@linux-foundation.org \
--cc=arbab@linux.vnet.ibm.com \
--cc=imammedo@redhat.com \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mhocko@suse.com \
--cc=qiuxishi@huawei.com \
--cc=vbabka@suse.cz \
--cc=vkuznets@redhat.com \
--cc=yasu.isimatu@gmail.com \
/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).