pids: increase pid_max based on num_possible_cpus
authorHedi Berriche <hedi@sgi.com>
Wed, 26 May 2010 21:44:06 +0000 (14:44 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 27 May 2010 16:12:51 +0000 (09:12 -0700)
commit72680a191b934377430032f93af15ef50aafb3a8
treee6f41babe66bf642204b3d92e793f5071739b1d2
parentbd4fb654e3a0d83ca8cb138c5e3e6e65407e119c
pids: increase pid_max based on num_possible_cpus

On a system with a substantial number of processors, the early default
pid_max of 32k will not be enough.  A system with 1664 CPU's, there are
25163 processes started before the login prompt.  It's estimated that with
2048 CPU's we will pass the 32k limit.  With 4096, we'll reach that limit
very early during the boot cycle, and processes would stall waiting for an
available pid.

This patch increases the early maximum number of pids available, and
increases the minimum number of pids that can be set during runtime.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Hedi Berriche <hedi@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Robin Holt <holt@sgi.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <gregkh@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: John Stoffel <john@stoffel.org>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/threads.h
kernel/pid.c