From: Ingo Molnar <mingo@elte.hu>
To: Andrew Morton <akpm@osdl.org>
Cc: andrea@suse.de, torvalds@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [lockup] Re: objrmap-core-1 (rmap removal for file mappings to avoid 4:4 in <=16G machines)
Date: Tue, 9 Mar 2004 12:49:24 +0100 [thread overview]
Message-ID: <20040309114924.GA4581@elte.hu> (raw)
In-Reply-To: <20040309030907.71a53a7c.akpm@osdl.org>
* Andrew Morton <akpm@osdl.org> wrote:
> > or run the attached test-mmap2.c code, which simulates a very small DB
> > app using only 1800 vmas per process: it only maps 8 MB of shm and
> > spawns 32 processes. This has an even more lethal effect than the
> > previous code.
>
> Do these tests actually make any forward progress at all, or is it some bug
> which has sent the kernel into a loop?
i think they make a forward progress so it's more of a DoS - but a very
effective one, especially considering that i didnt even try hard ...
what worries me is that there are apps that generate such vma patterns
(for various reasons).
I do believe that scanning ->i_mmap & ->i_mmap_shared is fundamentally
flawed.
Ingo
next prev parent reply other threads:[~2004-03-09 11:48 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-08 20:24 objrmap-core-1 (rmap removal for file mappings to avoid 4:4 in <=16G machines) Andrea Arcangeli
2004-03-08 20:39 ` Linus Torvalds
2004-03-08 21:23 ` Andrew Morton
2004-03-08 23:02 ` Andrea Arcangeli
2004-03-08 23:21 ` Andrew Morton
2004-03-08 23:40 ` Andrea Arcangeli
2004-03-09 0:10 ` Andrew Morton
2004-03-09 0:35 ` Andrea Arcangeli
2004-03-09 0:59 ` Andrew Morton
2004-03-09 8:31 ` Ingo Molnar
2004-03-09 8:44 ` William Lee Irwin III
2004-03-09 9:03 ` Ingo Molnar
2004-03-09 14:51 ` Andrea Arcangeli
2004-03-09 15:09 ` Ingo Molnar
2004-03-09 15:24 ` Andrea Arcangeli
2004-03-09 16:10 ` Ingo Molnar
2004-03-09 16:35 ` Andrea Arcangeli
2004-03-08 21:02 ` Andrew Morton
2004-03-08 22:34 ` Andrea Arcangeli
2004-03-09 2:46 ` Andrew Morton
2004-03-08 21:28 ` Arjan van de Ven
2004-03-08 23:08 ` Andrea Arcangeli
2004-03-09 7:47 ` Ingo Molnar
2004-03-09 15:21 ` Andrea Arcangeli
2004-03-09 15:36 ` Ingo Molnar
2004-03-09 16:33 ` Andrea Arcangeli
2004-03-09 17:23 ` Martin J. Bligh
2004-03-09 19:57 ` Ingo Molnar
2004-03-09 20:27 ` Andrea Arcangeli
2004-03-10 11:35 ` Ingo Molnar
2004-03-10 12:32 ` Andrea Arcangeli
2004-03-09 10:52 ` [lockup] " Ingo Molnar
2004-03-09 11:02 ` Ingo Molnar
2004-03-09 11:09 ` Andrew Morton
2004-03-09 11:49 ` Ingo Molnar [this message]
2004-03-09 12:32 ` William Lee Irwin III
2004-03-09 16:03 ` Andrea Arcangeli
2004-03-10 10:36 ` RFC anon_vma previous (i.e. full objrmap) Andrea Arcangeli
2004-03-10 10:40 ` RFC anon_vma preview " Andrea Arcangeli
2004-03-10 10:54 ` RFC anon_vma previous " Ingo Molnar
2004-03-11 6:52 ` anon_vma RFC2 Andrea Arcangeli
2004-03-11 13:23 ` Hugh Dickins
2004-03-11 13:56 ` Andrea Arcangeli
2004-03-11 21:54 ` Hugh Dickins
2004-03-12 1:47 ` Andrea Arcangeli
2004-03-12 2:20 ` Andrea Arcangeli
2004-03-12 3:28 ` Rik van Riel
2004-03-12 12:21 ` Andrea Arcangeli
2004-03-12 12:40 ` Rik van Riel
2004-03-12 13:11 ` Andrea Arcangeli
2004-03-12 16:25 ` Rik van Riel
2004-03-12 17:13 ` Andrea Arcangeli
2004-03-12 17:23 ` Rik van Riel
2004-03-12 17:44 ` Andrea Arcangeli
2004-03-12 18:18 ` Rik van Riel
2004-03-12 18:25 ` Linus Torvalds
2004-03-12 18:48 ` Rik van Riel
2004-03-12 19:02 ` Chris Friesen
2004-03-12 19:06 ` Rik van Riel
2004-03-12 19:10 ` Chris Friesen
2004-03-12 19:14 ` Rik van Riel
2004-03-12 20:27 ` Andrea Arcangeli
2004-03-12 20:32 ` Rik van Riel
2004-03-12 20:49 ` Andrea Arcangeli
2004-03-12 21:08 ` Jamie Lokier
2004-03-12 12:42 ` Andrea Arcangeli
2004-03-12 12:46 ` William Lee Irwin III
2004-03-12 13:24 ` Andrea Arcangeli
2004-03-12 13:40 ` William Lee Irwin III
2004-03-12 13:55 ` Hugh Dickins
2004-03-12 16:01 ` Andrea Arcangeli
2004-03-12 16:17 ` Linus Torvalds
2004-03-13 0:28 ` William Lee Irwin III
2004-03-13 14:43 ` Rik van Riel
2004-03-13 16:18 ` Linus Torvalds
2004-03-13 17:24 ` Hugh Dickins
2004-03-13 17:28 ` Rik van Riel
2004-03-13 17:41 ` Hugh Dickins
2004-03-13 18:08 ` Andrea Arcangeli
2004-03-13 17:54 ` Andrea Arcangeli
2004-03-13 17:55 ` Andrea Arcangeli
2004-03-13 18:57 ` Linus Torvalds
2004-03-13 19:14 ` Hugh Dickins
2004-03-13 17:48 ` Andrea Arcangeli
2004-03-13 17:33 ` Andrea Arcangeli
2004-03-13 17:53 ` Hugh Dickins
2004-03-13 18:13 ` Andrea Arcangeli
2004-03-13 19:35 ` Hugh Dickins
2004-03-13 17:57 ` Rik van Riel
2004-03-12 13:43 ` Hugh Dickins
2004-03-12 15:56 ` Andrea Arcangeli
2004-03-12 16:12 ` Hugh Dickins
2004-03-12 16:39 ` Andrea Arcangeli
2004-03-11 17:33 ` Andrea Arcangeli
2004-03-11 22:20 ` Rik van Riel
2004-03-11 23:43 ` Hugh Dickins
2004-03-12 3:20 ` Rik van Riel
2004-03-09 17:22 ` [lockup] Re: objrmap-core-1 (rmap removal for file mappings to avoid 4:4 in <=16G machines) Rik van Riel
2004-03-09 17:56 ` Andrea Arcangeli
2004-03-09 15:59 ` Andrea Arcangeli
2004-03-09 16:07 ` Ingo Molnar
2004-03-09 16:08 ` Ingo Molnar
2004-03-09 16:39 ` Andrea Arcangeli
2004-03-09 19:33 ` Ingo Molnar
2004-03-09 16:39 ` Andrea Arcangeli
2004-03-09 15:41 ` Andrea Arcangeli
2004-03-15 19:47 ` Marcelo Tosatti
2004-03-15 22:00 ` Andrea Arcangeli
2004-03-16 7:39 ` Marcelo Tosatti
2004-03-16 13:50 ` Andrea Arcangeli
[not found] <20040310080000.GA30940@dualathlon.random>
2004-03-10 13:01 ` Rik van Riel
2004-03-10 13:50 ` Andrea Arcangeli
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