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Date: Tue, 23 Oct 2001 16:05:55 -0500
From: Dave McCracken <dmccr@us.ibm.com>
To: Rik van Riel <riel@conectiva.com.br>
cc: Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: Issue with max_threads (and other resources) and highmem
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--On Tuesday, October 23, 2001 18:52:35 -0200 Rik van Riel
<riel@conectiva.com.br> wrote:

> I submitted a patch a while ago to set the number way lower,
> which was accepted by Alan and in the -ac kernels. A few months
> later Linus followed and changed the limit in his kernels, too.

Ok, that's what I get for reading the comment and not deciphering the
code...  The actual calculation is mempages / (THREAD_SIZE/PAGE_SIZE) / 8
where THREAD_SIZE is 2 pages on i386.  If I read it right this means it's
limiting it to 1/8 physical memory instead of half.

But there's still a problem.  The value for mempages is all of physical
memory including highmem, so a machine with a sufficient amount of high
memory can set max_threads to a value way too high, given that most if not
all of the resources it's trying to limit have to come from normal memory
and not high memory.

Dave McCracken

======================================================================
Dave McCracken          IBM Linux Base Kernel Team      1-512-838-3059
dmccr@us.ibm.com                                        T/L   678-3059

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