From: Herbert Poetzl <herbert@13thfloor.at>
To: Dave Hansen <hansendc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Andrew Morton <akpm@linux-foundation.org>,
containers@lists.osdl.org, menage@google.com, xemul@sw.ru,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel@vger.kernel.org
Subject: Re: controlling mmap()'d vs read/write() pages
Date: Fri, 23 Mar 2007 19:16:26 +0100 [thread overview]
Message-ID: <20070323181626.GA17007@MAIL.13thfloor.at> (raw)
In-Reply-To: <1174668073.8323.63.camel@localhost.localdomain>
On Fri, Mar 23, 2007 at 09:41:12AM -0700, Dave Hansen wrote:
> On Fri, 2007-03-23 at 04:12 -0600, Eric W. Biederman wrote:
> > 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 truly understand your point here. But, I don't think this thought
> exercise is really helpful here. In a pure sense, nothing is keeping
> an unmapped page cache file in memory, other than the user's prayers.
> But, please don't discount their prayers, it's what they want!
>
> I seem to remember a quote attributed to Alan Cox around OLS time last
> year, something about any memory controller being able to be fair,
> fast, and accurate. Please pick any two, but only two. Alan, did I get
> close?
so we would pick fair and fast then :)
> To me, one of the keys of Linux's "global optimizations" is being able
> to use any memory globally for its most effective purpose, globally
> (please ignore highmem :). Let's say I have a 1GB container on a
> machine that is at least 100% committed. I mmap() a 1GB file and touch
> the entire thing (I never touch it again). I then go open another 1GB
> file and r/w to it until the end of time. I'm at or below my RSS limit,
> but that 1GB of RAM could surely be better used for the second file.
> How do we do this if we only account for a user's RSS? Does this fit
> into Alan's unfair bucket? ;)
what's the difference to a normal Linux system here?
when low on memory, the system will reclaim pages, and
guess what pages will be reclaimed first ...
> Also, in a practical sense, it is also a *LOT* easier to describe to a
> customer that they're getting 1GB of RAM than >=20GB/hr of bandwidth
> from the disk.
if you want something which is easy to describe for the
'customer', then a VM is what you are looking for, it has
a perfectly well defined amount of resources which will
not be shared or used by other machines ...
> -- Dave
>
> P.S. Do we have an quotas on ramfs? If we have an ramfs filesystems,
> what keeps the containerized users from just filling up RAM?
tmpfs has hard limits, you simply specify it on mount
none /tmp tmpfs size=16m,mode=1777 0 0
best,
Herbert
> _______________________________________________
> Containers mailing list
> Containers@lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/containers
next prev parent reply other threads:[~2007-03-23 18:17 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
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 [this message]
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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