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Date: Fri, 22 Feb 2002 16:41:43 -0800
From: William Lee Irwin III <wli@holomorphy.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Larson <plars@austin.ibm.com>, marcelo@conectiva.com.br,
        linux-kernel@vger.kernel.org, manfred@colorfullife.com
Subject: Re: [PATCH] 2.4.18-rc2 Fix for get_pid hang
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At some point in the past, Paul Larson wrote:
>> This was made against 2.4.18-rc2 but applies cleanly against
>> 2.4.18-rc4.  This is a fix for a problem where if we run out of
>> available pids, get_pid will hang the system while it searches
>> through the tasks for an available pid forever.

On Sat, Feb 23, 2002 at 12:29:47AM +0000, Alan Cox wrote:
> Wouldn't it be a much cleaner patch to limit the maximum number of
> processes to less than the number of pids available. You seem to be
> fixing a non problem by adding branches to the innards of a loop.

I've seen this one before. It seems to kick in at 11K processes, where
one would normally expect it much higher... so I'm not sure a constant
upper bound on that counter suffices. Maybe clashes of pid's with pgrp's
and sessions and tgrps are what does that, maybe it's something else.

and of course:

#include <stdgeek.h>  /* Any hope of a non-O(tasks) solution? */


Cheers,
Bill