From: Nick Piggin <nickpiggin@yahoo.com.au>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Hansen <hansendc@us.ibm.com>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
containers@lists.osdl.org, linux-kernel@vger.kernel.org,
menage@google.com, Andrew Morton <akpm@linux-foundation.org>,
xemul@sw.ru
Subject: Re: controlling mmap()'d vs read/write() pages
Date: Fri, 23 Mar 2007 21:47:45 +1100 [thread overview]
Message-ID: <4603B051.8000108@yahoo.com.au> (raw)
In-Reply-To: <m1tzwc5kw6.fsf@ebiederm.dsl.xmission.com>
Eric W. Biederman wrote:
> Nick Piggin <nickpiggin@yahoo.com.au> writes:
>
>
>>Eric W. Biederman wrote:
>>
>>>Dave Hansen <hansendc@us.ibm.com> writes:
>>>
>>>
>>>
>>>>So, I think we have a difference of opinion. I think it's _all_ about
>>>>memory pressure, and you think it is _not_ about accounting for memory
>>>>pressure. :) Perhaps we mean different things, but we appear to
>>>>disagree greatly on the surface.
>>>
>>>
>>>I think it is about preventing a badly behaved container from having a
>>>significant effect on the rest of the system, and in particular other
>>>containers on the system.
>>
>>That's Dave's point, I believe. Limiting mapped memory may be
>>mostly OK for well behaved applications, but it doesn't do anything
>>to stop bad ones from effectively DoSing the system or ruining any
>>guarantees you might proclaim (not that hard guarantees are always
>>possible without using virtualisation anyway).
>>
>>This is why I'm surprised at efforts that go to such great lengths
>>to get accounting "just right" (but only for mmaped memory). You
>>may as well not even bother, IMO.
>>
>>Give me an RSS limit big enough to run a couple of system calls and
>>a loop...
>
>
> Would any of them work on a system on which every filesystem was on
> ramfs, and there was no swap? If not then they are not memory attacks
> but I/O attacks.
>
> I completely concede that you can DOS the system with I/O if that is
> not limited as well.
>
> My point is that is not a memory problem but a disk I/O problem which is
> much easier to and cheaper to solve. Disk I/O is fundamentally a slow
> path which makes it hard to modify it in a way that negatively affects
> system performance.
>
> I don't think with a memory RSS limit you can DOS the system in a way
> that is purely about memory. You have to pick a different kind of DOS
> attack.
It can be done trivially without performing any IO or swap, yes.
--
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com
next prev parent reply other threads:[~2007-03-23 10:47 UTC|newest]
Thread overview: 129+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-06 14:42 [RFC][PATCH 0/7] Resource controllers based on process containers Pavel Emelianov
2007-03-06 14:49 ` [RFC][PATCH 1/7] Resource counters Pavel Emelianov
2007-03-07 4:03 ` Balbir Singh
2007-03-07 7:19 ` Pavel Emelianov
2007-03-09 16:37 ` Herbert Poetzl
2007-03-11 9:01 ` Pavel Emelianov
2007-03-11 19:00 ` Eric W. Biederman
2007-03-12 1:16 ` Herbert Poetzl
2007-03-13 9:09 ` Eric W. Biederman
2007-03-13 9:27 ` Pavel Emelianov
2007-03-13 9:49 ` [Devel] " Kirill Korotaev
2007-03-13 15:21 ` Herbert Poetzl
2007-03-13 15:41 ` Pavel Emelianov
2007-03-13 16:07 ` Srivatsa Vaddagiri
2007-03-14 7:12 ` Pavel Emelianov
2007-03-15 16:51 ` Eric W. Biederman
2007-03-13 16:32 ` Herbert Poetzl
2007-03-06 14:55 ` [RFC][PATCH 2/7] RSS controller core Pavel Emelianov
2007-03-06 22:00 ` Andrew Morton
2007-03-09 16:48 ` Herbert Poetzl
2007-03-11 9:08 ` Pavel Emelianov
2007-03-11 14:32 ` Herbert Poetzl
2007-03-11 15:04 ` Pavel Emelianov
2007-03-12 0:41 ` Herbert Poetzl
2007-03-12 8:31 ` Pavel Emelianov
2007-03-12 9:55 ` Balbir Singh
2007-03-12 23:43 ` Herbert Poetzl
2007-03-13 1:57 ` Balbir Singh
2007-03-13 2:24 ` Srivatsa Vaddagiri
2007-03-13 16:06 ` Herbert Poetzl
2007-03-11 12:26 ` Kirill Korotaev
2007-03-11 12:51 ` Andrew Morton
2007-03-11 15:51 ` Balbir Singh
2007-03-11 19:34 ` Eric W. Biederman
2007-03-12 9:23 ` [Devel] " Kirill Korotaev
2007-03-13 9:26 ` Eric W. Biederman
2007-03-13 15:43 ` Kirill Korotaev
2007-03-12 1:00 ` Herbert Poetzl
2007-03-12 9:02 ` Pavel Emelianov
2007-03-12 21:11 ` Herbert Poetzl
2007-03-13 7:17 ` Pavel Emelianov
2007-03-13 15:05 ` Herbert Poetzl
2007-03-13 15:32 ` Pavel Emelianov
2007-03-13 15:10 ` Kirill Korotaev
2007-03-13 15:11 ` Herbert Poetzl
2007-03-13 15:54 ` Kirill Korotaev
2007-03-12 18:42 ` Dave Hansen
2007-03-12 22:41 ` Herbert Poetzl
2007-03-12 23:02 ` Dave Hansen
2007-03-18 16:58 ` Eric W. Biederman
2007-03-13 6:04 ` Andrew Morton
2007-03-13 10:19 ` [Devel] " Kirill Korotaev
2007-03-13 11:48 ` Andrew Morton
2007-03-13 14:59 ` Herbert Poetzl
2007-03-13 17:05 ` Dave Hansen
2007-03-14 15:38 ` Mel Gorman
2007-03-14 20:42 ` Dave Hansen
2007-03-20 18:57 ` Mel Gorman
2007-03-18 22:44 ` [Devel] " Paul Menage
2007-03-19 17:41 ` Eric W. Biederman
2007-03-13 17:26 ` Dave Hansen
2007-03-13 19:09 ` Alan Cox
2007-03-13 20:28 ` Dave Hansen
2007-03-16 0:55 ` Eric W. Biederman
2007-03-16 16:31 ` Dave Hansen
2007-03-16 18:54 ` Eric W. Biederman
2007-03-16 19:46 ` Dave Hansen
2007-03-18 17:42 ` Eric W. Biederman
2007-03-19 15:48 ` Herbert Poetzl
2007-03-20 16:15 ` controlling mmap()'d vs read/write() pages Dave Hansen
2007-03-20 21:19 ` Eric W. Biederman
2007-03-23 0:51 ` Herbert Poetzl
2007-03-23 5:57 ` Nick Piggin
2007-03-23 10:12 ` Eric W. Biederman
2007-03-23 10:47 ` Nick Piggin [this message]
2007-03-23 12:21 ` Eric W. Biederman
2007-03-28 7:33 ` Nick Piggin
2007-03-23 16:41 ` Dave Hansen
2007-03-23 18:16 ` Herbert Poetzl
2007-03-28 9:18 ` Balbir Singh
2007-03-14 16:47 ` [RFC][PATCH 2/7] RSS controller core Mel Gorman
2007-03-07 5:37 ` Balbir Singh
2007-03-07 7:27 ` Pavel Emelianov
2007-03-06 14:58 ` [RFC][PATCH 3/7] Data structures changes for RSS accounting Pavel Emelianov
2007-03-11 19:13 ` Eric W. Biederman
2007-03-12 16:16 ` Kirill Korotaev
2007-03-12 16:48 ` Dave Hansen
2007-03-12 17:19 ` Pavel Emelianov
2007-03-12 17:27 ` Dave Hansen
2007-03-13 7:10 ` Pavel Emelianov
2007-03-12 17:21 ` Balbir Singh
2007-03-06 15:00 ` [RFC][PATCH 4/7] RSS accounting hooks over the code Pavel Emelianov
2007-03-11 19:14 ` Eric W. Biederman
2007-03-12 16:23 ` Kirill Korotaev
2007-03-12 16:50 ` Dave Hansen
2007-03-12 17:07 ` Kirill Korotaev
2007-03-12 17:33 ` Dave Hansen
2007-03-13 9:43 ` Eric W. Biederman
2007-03-12 23:54 ` Herbert Poetzl
2007-03-13 9:58 ` Eric W. Biederman
2007-03-13 10:25 ` Nick Piggin
2007-03-13 16:01 ` Eric W. Biederman
2007-03-14 3:51 ` Nick Piggin
2007-03-14 6:42 ` Balbir Singh
2007-03-14 6:57 ` Nick Piggin
2007-03-14 7:48 ` Balbir Singh
2007-03-14 13:25 ` Vaidyanathan Srinivasan
2007-03-14 13:49 ` Nick Piggin
2007-03-14 14:43 ` Vaidyanathan Srinivasan
2007-03-14 16:16 ` Kirill Korotaev
2007-03-15 5:01 ` Nick Piggin
2007-03-15 5:44 ` Balbir Singh
2007-03-28 20:15 ` Ethan Solomita
2007-03-14 15:37 ` Cedric Le Goater
2007-03-14 15:45 ` Pavel Emelianov
2007-03-06 15:03 ` [RFC][PATCH 5/7] Per-container OOM killer and page reclamation Pavel Emelianov
2007-03-09 21:21 ` Balbir Singh
2007-03-11 8:41 ` Pavel Emelianov
2007-03-06 15:04 ` [RFC][PATCH 6/7] Account for the number of tasks within container Pavel Emelianov
2007-03-07 2:00 ` Paul Menage
2007-03-07 7:13 ` Pavel Emelianov
2007-03-08 13:49 ` Paul Menage
2007-03-11 8:36 ` Pavel Emelianov
2007-03-06 15:07 ` [RFC][PATCH 7/7] Account for the number of files opened " Pavel Emelianov
2007-03-07 2:02 ` [RFC][PATCH 0/7] Resource controllers based on process containers Paul Menage
2007-03-07 7:30 ` Pavel Emelianov
2007-03-07 6:52 ` Balbir Singh
2007-03-07 7:32 ` Pavel Emelianov
2007-03-07 9:43 ` Kirill Korotaev
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