From: Michal Hocko <mhocko@kernel.org>
To: Xishi Qiu <qiuxishi@huawei.com>
Cc: Xuzhichuang <xuzhichuang@huawei.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Songjiangtao (mygirlsjt)" <songjiangtao.song@huawei.com>,
"Zhangwei (FF)" <zw.zhang@huawei.com>
Subject: Re: [BUG REPORT] OOM Killer is invoked while the system still has much memory
Date: Tue, 14 Jul 2015 11:28:43 +0200 [thread overview]
Message-ID: <20150714092842.GB17660@dhcp22.suse.cz> (raw)
In-Reply-To: <55A4D300.5030704@huawei.com>
On Tue 14-07-15 17:14:40, Xishi Qiu wrote:
> On 2015/7/14 17:00, Michal Hocko wrote:
>
> > On Tue 14-07-15 16:42:16, Xishi Qiu wrote:
> >> On 2015/7/14 16:15, Michal Hocko wrote:
> >>
> >>> On Tue 14-07-15 07:11:34, Xuzhichuang wrote:
> > [...]
> >>>> Jul 10 12:33:03 BMS_CNA04 kernel: [18136514.138968] DMA32: 188513*4kB 29459*8kB 2*16kB 2*32kB 1*64kB 0*128kB 0*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB = 990396kB
> >>>
> >>> Moreover your allocation request was oreder 2 and you do not have much
> >>> memory there because most of the free memory is in order-0-2.
> >>>
> >>
> >> Hi Michal,
> >>
> >> order=2 -> alloc 16kb memory, and DMA32 still has 2*16kB 2*32kB 1*64kB 1*512kB,
> >> so you mean this large buddy block was reclaimed during the moment of oom and
> >> print, right?
> >
> > Not really. Those high order blocks are inaccessible for your GFP_KERNEL
> > allocation. See __zone_watermark_ok.
> >
>
> I know, some of them are from reserved memory(MIGRATE_RESERVE), right?
No. The watermark is calculated per order. And you have almost all the
free memory in the lower orders. From a quick glance it seems that even
order-1 allocations wouldn't fit into min watermark.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2015-07-14 9:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-14 7:11 [BUG REPORT] OOM Killer is invoked while the system still has much memory Xuzhichuang
2015-07-14 8:15 ` Michal Hocko
2015-07-14 8:42 ` Xishi Qiu
2015-07-14 9:00 ` Michal Hocko
2015-07-14 9:14 ` Xishi Qiu
2015-07-14 9:28 ` Michal Hocko [this message]
2015-07-14 9:50 ` Xishi Qiu
2015-07-15 0:09 ` David Rientjes
2015-07-15 1:46 ` 答复: " Xuzhichuang
2015-07-15 1:57 ` David Rientjes
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=20150714092842.GB17660@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=qiuxishi@huawei.com \
--cc=songjiangtao.song@huawei.com \
--cc=xuzhichuang@huawei.com \
--cc=zw.zhang@huawei.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).