From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Michal Hocko <mhocko@suse.cz>
Cc: kosaki.motohiro@jp.fujitsu.com,
LKML <linux-kernel@vger.kernel.org>,
Jack Steiner <steiner@sgi.com>,
Lee Schermerhorn <lee.schermerhorn@hp.com>,
Christoph Lameter <cl@linux-foundation.org>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Paul Menage <menage@google.com>, Robin Holt <holt@sgi.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: cpusets: randomize node rotor used in cpuset_mem_spread_node()
Date: Fri, 15 Apr 2011 16:18:45 +0900 (JST) [thread overview]
Message-ID: <20110415161831.12F8.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <20110414160145.0830.A69D9226@jp.fujitsu.com>
Oops.
I should have look into !mempolicy part too.
I'm sorry.
> diff --git a/kernel/fork.c b/kernel/fork.c
> index e7548de..f59c686 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1119,6 +1119,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
> }
> mpol_fix_fork_child_flag(p);
> #endif
> +#ifdef CONFIG_CPUSETS
> + p->cpuset_mem_spread_rotor = node_random(&p->mems_allowed);
> + p->cpuset_slab_spread_rotor = node_random(&p->mems_allowed);
> +#endif
Michal, I think this should be
#ifdef CONFIG_CPUSETS
if (cpuset_do_page_mem_spread())
p->cpuset_mem_spread_rotor = node_random(&p->mems_allowed);
if (cpuset_do_slab_mem_spread())
p->cpuset_slab_spread_rotor = node_random(&p->mems_allowed);
#endif
because 99.999% people don't use cpuset's spread mem/slab feature and
get_random_int() isn't zero cost.
What do you think?
next prev parent reply other threads:[~2011-04-15 7:18 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-13 14:35 Michal Hocko
2011-04-14 2:19 ` KOSAKI Motohiro
2011-04-14 6:51 ` Michal Hocko
2011-04-14 7:01 ` KOSAKI Motohiro
2011-04-15 7:18 ` KOSAKI Motohiro [this message]
2011-04-15 8:20 ` [PATCH v2] " Michal Hocko
2011-04-15 8:29 ` KOSAKI Motohiro
2011-04-15 8:31 ` Michal Hocko
2011-04-15 23:42 ` David Rientjes
2011-04-18 8:42 ` [PATCH incremental] cpusets: initialize spread rotor lazily Michal Hocko
2011-04-18 20:19 ` David Rientjes
2011-04-18 21:29 ` Michal Hocko
2011-04-19 1:15 ` David Rientjes
2011-05-26 22:33 ` [PATCH v2] cpusets: randomize node rotor used in cpuset_mem_spread_node() Andrew Morton
2011-05-27 12:47 ` Michal Hocko
2011-05-27 19:07 ` David Rientjes
2011-05-27 23:17 ` Michal Hocko
2011-05-27 23:27 ` David Rientjes
2011-05-27 23:40 ` Michal Hocko
2011-05-27 21:20 ` Andrew Morton
2011-05-27 23:17 ` Michal Hocko
2011-05-27 23:30 ` David Rientjes
2011-05-27 23:38 ` Michal Hocko
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