From: Michal Hocko <mhocko@kernel.org>
To: "Huang, Ying" <ying.huang@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>,
lkp@01.org, LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>,
Vitaly Wool <vitalywool@gmail.com>,
David Rientjes <rientjes@google.com>,
Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Vlastimil Babka <vbabka@suse.cz>,
Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: [lkp] [mm, page_alloc] 43993977ba: +88% OOM possibility
Date: Fri, 30 Oct 2015 11:38:30 +0100 [thread overview]
Message-ID: <20151030103830.GJ18429@dhcp22.suse.cz> (raw)
In-Reply-To: <87si4szrzf.fsf@yhuang-dev.intel.com>
On Fri 30-10-15 16:21:40, Huang, Ying wrote:
> Michal Hocko <mhocko@kernel.org> writes:
>
> > On Wed 28-10-15 13:36:02, kernel test robot wrote:
> >> FYI, we noticed the below changes on
> >>
> >> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> >> commit 43993977baecd838d66ccabc7f682342fc6ff635 ("mm, page_alloc:
> >> distinguish between being unable to sleep, unwilling to sleep and
> >> avoiding waking kswapd")
> >>
> >> We found the OOM possibility increased 88% in a virtual machine with 1G memory.
> >
> > Could you provide dmesg output from this test?
>
> Sure, Attached.
I can only see a single allocation failure warning:
kworker/u4:1: page allocation failure: order:0, mode:0x2204000
This is obviously a non sleeping allocation with ___GFP_KSWAPD_RECLAIM
set. ___GFP_HIGH (aka access to memory reserves) is not required so a
failure of such an allocation is something to be expected.
[ 2294.616369] Workqueue: btrfs-submit btrfs_submit_helper
[ 2294.616369] 0000000000000000 ffff88000d38f5e0 ffffffff8173f84c 0000000000000000
[ 2294.616369] ffff88000d38f678 ffffffff811abaee 00000000ffffffff 000000010038f618
[ 2294.616369] ffff8800584e4148 00000000ffffffff ffff8800584e2f00 0000000000000001
[ 2294.616369] Call Trace:
[ 2294.616369] [<ffffffff8173f84c>] dump_stack+0x4b/0x63
[ 2294.616369] [<ffffffff811abaee>] warn_alloc_failed+0x125/0x13d
[ 2294.616369] [<ffffffff811aecce>] __alloc_pages_nodemask+0x7c9/0x915
[ 2294.616369] [<ffffffff811ecc7b>] kmem_getpages+0x91/0x155
[ 2294.616369] [<ffffffff811eef0d>] fallback_alloc+0x1cc/0x24c
[ 2294.616369] [<ffffffff811eed32>] ____cache_alloc_node+0x151/0x160
[ 2294.616369] [<ffffffff811ef1ed>] __kmalloc+0xb0/0x134
[ 2294.616369] [<ffffffff8105d7a5>] ? sched_clock+0x9/0xb
[ 2294.616369] [<ffffffff8187d929>] ? virtqueue_add+0x78/0x37f
[ 2294.616369] [<ffffffff8187d929>] virtqueue_add+0x78/0x37f
[ 2294.616369] [<ffffffff81114f72>] ? __lock_acquire+0x751/0xf55
[ 2294.616369] [<ffffffff8187dca6>] virtqueue_add_sgs+0x76/0x85
The patch you are referring shouldn't make any change in this path
because alloc_indirect which I expect is the allocation failing here
does:
gfp &= ~(__GFP_HIGHMEM | __GFP_HIGH)
and that came in via b92b1b89a33c ("virtio: force vring descriptors to
be allocated from lowmem").
Are there more failed allocations during the test? The subject would
suggest so.
Thanks!
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2015-10-30 10:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-28 5:36 kernel test robot
2015-10-29 14:24 ` Michal Hocko
2015-10-30 8:21 ` Huang, Ying
2015-10-30 10:38 ` Michal Hocko [this message]
2015-11-01 23:20 ` Huang, Ying
2015-11-02 7:45 ` Michal Hocko
2015-11-02 8:55 ` Huang, Ying
2015-11-02 9:53 ` Michal Hocko
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=20151030103830.GJ18429@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@01.org \
--cc=mgorman@techsingularity.net \
--cc=riel@redhat.com \
--cc=rientjes@google.com \
--cc=sfr@canb.auug.org.au \
--cc=vbabka@suse.cz \
--cc=vitalywool@gmail.com \
--cc=ying.huang@linux.intel.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
all inboxes | Powered by JetHome®