linux-kernel - Re: [PATCH v3]mm/oom-kill: direct hardware access processes should get bonus

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 6 Jan 2011 09:55:28 +0900
From:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To:	"Figo.zhang" <zhangtianfei@...dcoretech.com>
Cc:	lkml <linux-kernel@...r.kernel.org>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	Andrew Morton <akpm@...l.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"Figo.zhang" <figo1802@...il.com>,
	"rientjes@...gle.com" <rientjes@...gle.com>,
	Wu Fengguang <fengguang.wu@...el.com>
Subject: Re: [PATCH v3]mm/oom-kill: direct hardware access processes should
 get bonus

On Tue, 04 Jan 2011 16:56:47 +0800
"Figo.zhang" <zhangtianfei@...dcoretech.com> wrote:

> On 01/04/2011 04:28 PM, KAMEZAWA Hiroyuki wrote:
> > On Tue, 04 Jan 2011 15:51:44 +0800
> > "Figo.zhang"<zhangtianfei@...dcoretech.com>  wrote:
> >
> >>
> >> i had send the patch to protect the hardware access processes for
> >> oom-killer before, but rientjes have not agree with me.
> >>
> >> but today i catch log from my desktop. oom-killer have kill my "minicom"
> >> and "Xorg". so i think it should add protection about it.
> >>
> >
> > Off topic.
> >
> > In this log, I found
> >
> >>> Jan  4 15:22:55 figo-desktop kernel: Free swap  = -1636kB
> >>> Jan  4 15:22:55 figo-desktop kernel: Total swap = 0kB
> >>> Jan  4 15:22:55 figo-desktop kernel: 515070 pages RAM
> >
> > ... This means total_swap_pages = 0 while pages are read-in at swapoff.
> >
> > Let's see 'points' for oom
> > ==
> > points = (get_mm_rss(p->mm) + get_mm_counter(p->mm, MM_SWAPENTS)) * 1000 /
> >                          totalpages;
> > ==
> >
> > Here, totalpages = total_ram + total_swap but totalswap is 0 here.
> >
> > So, points can be>  1000, easily.
> > (This seems not to be related to the Xorg's death itself)
> 
> total_swap is 0, so
> totalpages = total_ram,
> get_mm_counter(p->mm, MM_SWAPENTS) = 0,
> 
> so
> points = (get_mm_rss(p->mm)) * 1000 / totalpages;
> 
> so points canot larger than 1000.

mm_counter's swap count is reduced only when swapents are removed from
page table. But total_swap is reduced to be 0 before try_to_unuse().


Thanks,
-Kame



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/