From: Jonathan Lundell <linux@lundell-bros.com>
To: root@chaos.analogic.com, "Jörn Engel" <joern@wohnheim.fh-wedel.de>
Cc: Linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: top stack (l)users for 2.5.69
Date: Wed, 7 May 2003 10:13:55 -0700 [thread overview]
Message-ID: <p05210601badeeb31916c@[207.213.214.37]> (raw)
In-Reply-To: <Pine.LNX.4.53.0305071008080.11871@chaos>
At 10:16am -0400 5/7/03, Richard B. Johnson wrote:
>Nope. Just don't steal thousands of CPU cycles to make something
>"pretty". Obviously something called recursively with a 2k buffer
>on the stack is going to break. However one has to actually
>look at the code and determine the best (if any) way to reduce
>stack usage. For instance, some persons may just "like" 0x400 for
>the size of a temporary buffer when, in fact, 29 bytes are actually
>used.
>
>FYI, one can make a module that will show the maximum amount
>of stack ever used IFF the stack gets zeroed before use upon
>kernel startup. Would this be useful or has it already been
>done?
There's at least one patch floating around to do that; we've used it
to help track down some stack overflow problems.
Does 2.5 use a separate interrupt stack? (Excuse my ignorance; I
haven't been paying attention.) Total stack-page usage in the 2.4
model, at any rate, is the sum of the task struct, the usage of any
task-level thread (system calls, pretty much), any softirq (including
the network protocol & routing handlers, and any netfilter modules),
and some number of possibly-nested hard interrupts.
That adds up.
One thing that would help (aside from separate interrupt stacks)
would be a guard page below the stack. That wouldn't require any
physical memory to be reserved, and would provide positive indication
of stack overflow without significant runtime overhead.
--
/Jonathan Lundell.
next prev parent reply other threads:[~2003-05-07 17:01 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-07 13:20 top stack (l)users for 2.5.69 Jörn Engel
2003-05-07 13:45 ` Richard B. Johnson
2003-05-07 13:56 ` Jörn Engel
2003-05-07 14:16 ` Richard B. Johnson
2003-05-07 17:13 ` Jonathan Lundell [this message]
2003-05-07 17:40 ` Richard B. Johnson
2003-05-07 18:12 ` Roland Dreier
2003-05-07 18:28 ` Richard B. Johnson
2003-05-07 18:44 ` Timothy Miller
2003-05-07 18:46 ` Roland Dreier
2003-05-07 19:30 ` Richard B. Johnson
2003-05-07 19:42 ` Roland Dreier
2003-05-07 20:04 ` Richard B. Johnson
2003-05-07 20:23 ` Roland Dreier
2003-05-07 20:42 ` Timothy Miller
2003-05-08 9:06 ` Jörn Engel
2003-05-08 11:33 ` Richard B. Johnson
2003-05-08 12:00 ` Helge Hafting
2003-05-08 15:42 ` Timothy Miller
2003-05-09 8:57 ` Miles Bader
2003-05-09 16:50 ` Timothy Miller
2003-05-08 16:47 ` Davide Libenzi
2003-05-07 18:51 ` Davide Libenzi
2003-05-07 19:22 ` Richard B. Johnson
2003-05-07 19:31 ` Davide Libenzi
2003-05-07 19:39 ` Hua Zhong
2003-05-07 21:47 ` Martin J. Bligh
2003-05-08 10:29 ` David Howells
2003-05-07 17:55 ` Jörn Engel
2003-05-07 16:20 ` Martin J. Bligh
2003-05-07 19:01 ` Dave Hansen
2003-05-07 20:06 ` Jörn Engel
2003-05-07 20:14 ` Dave Hansen
2003-05-08 8:41 ` Jörn Engel
2003-05-08 16:51 ` Dave Hansen
2003-05-08 22:12 ` Jörn Engel
2003-05-07 21:30 ` Jesse Pollard
2003-05-07 21:54 ` Timothy Miller
2003-05-07 22:01 ` Jesse Pollard
2003-05-07 14:33 ` Torsten Landschoff
2003-05-07 14:47 ` William Lee Irwin III
2003-05-07 15:04 ` Torsten Landschoff
2003-05-07 16:01 ` William Lee Irwin III
2003-05-08 15:36 ` Ingo Oeser
2003-05-08 18:04 ` William Lee Irwin III
2003-05-07 15:23 ` Timothy Miller
2003-05-07 15:47 ` William Lee Irwin III
2003-05-07 16:49 ` Jörn Engel
2003-05-07 17:18 ` Davide Libenzi
2003-05-07 17:40 ` Jörn Engel
2003-05-07 18:35 ` Davide Libenzi
2003-05-07 19:45 ` Jörn Engel
2003-05-07 18:23 ` William Lee Irwin III
2003-05-07 17:38 ` William Lee Irwin III
2003-05-07 17:47 ` Jörn Engel
2003-05-07 14:49 ` Richard B. Johnson
2003-05-07 18:36 ` Linus Torvalds
2003-05-07 19:17 ` Jeff Garzik
2003-05-07 20:38 ` Randy.Dunlap
2003-05-07 21:27 ` Marcus Alanen
2003-05-07 21:27 ` Randy.Dunlap
2003-05-08 15:10 ` Ingo Oeser
2003-05-08 17:12 ` Randy.Dunlap
2003-05-07 19:38 Chuck Ebbert
2003-05-08 14:08 Chuck Ebbert
2003-05-08 18:04 ` Jonathan Lundell
2003-05-08 19:05 ` Timothy Miller
2003-05-08 21:00 ` Jonathan Lundell
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