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From: Robin Holt <holt@sgi.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Robin Holt <holt@sgi.com>,
	linux-kernel@vger.kernel.org, Pavel Emelyanov <xemul@openvz.org>,
	Oleg Nesterov <oleg@tv-sign.ru>,
	Sukadev Bhattiprolu <sukadev@us.ibm.com>,
	Paul Menage <menage@google.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [Patch] Scale pidhash_shift/pidhash_size up based on num_possible_cpus().
Date: Thu, 31 Jul 2008 15:08:35 -0500	[thread overview]
Message-ID: <20080731200835.GK9663@sgi.com> (raw)
In-Reply-To: <m1iqul25rk.fsf@frodo.ebiederm.org>

Like so???

I have not tested this yet.

---

Set the upper limit for the pidhash_shift based upon PID_MAX_LIMIT.

Signed-off-by: Robin Holt <holt@sgi.com>


Index: contention_unroll/kernel/pid.c
===================================================================
--- contention_unroll.orig/kernel/pid.c	2008-07-31 11:59:21.154284073 -0500
+++ contention_unroll/kernel/pid.c	2008-07-31 15:07:21.909158788 -0500
@@ -504,7 +504,7 @@ void __init pidhash_init(void)
 	unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT);
 
 	pidhash_shift = max(4, fls(megabytes * 4));
-	pidhash_shift = min(12, pidhash_shift);
+	pidhash_shift = min(fls(PID_MAX_LIMIT) - 6, pidhash_shift);
 	pidhash_size = 1 << pidhash_shift;
 
 	printk("PID hash table entries: %d (order: %d, %Zd bytes)\n",

  reply	other threads:[~2008-07-31 20:08 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-31 17:00 [Patch] Scale pidhash_shift/pidhash_size up based on num_possible_cpus() Robin Holt
2008-07-31 18:35 ` Eric W. Biederman
2008-07-31 19:32   ` Robin Holt
2008-07-31 19:49     ` Eric W. Biederman
2008-07-31 20:08       ` Robin Holt [this message]
2008-07-31 22:04         ` Eric W. Biederman
2008-08-01 12:04           ` Robin Holt
2008-08-01 18:27             ` Eric W. Biederman
2008-08-01 19:13               ` Robin Holt
2008-08-01 19:59                 ` Eric W. Biederman
2008-08-04 13:11                   ` Stephen Champion
2008-08-04 20:36                     ` Eric W. Biederman
2008-08-04 23:58                       ` Robin Holt
2008-08-05  0:38                         ` Eric W. Biederman
2008-08-06  3:21                           ` Stephen Champion
2008-08-01 18:49             ` Linus Torvalds

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