From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Eric B Munson <ebmunson@us.ibm.com>
Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, mel@linux.vnet.ibm.com,
cl@linux-foundation.org
Subject: Re: [PATCH V3] Fix Committed_AS underflow
Date: Mon, 20 Apr 2009 09:15:20 -0700 [thread overview]
Message-ID: <1240244120.32604.278.camel@nimitz> (raw)
In-Reply-To: <1240218590-16714-1-git-send-email-ebmunson@us.ibm.com>
On Mon, 2009-04-20 at 10:09 +0100, Eric B Munson wrote:
> 1. Change NR_CPUS to min(64, NR_CPUS)
> This will limit the amount of possible skew on kernels compiled for very
> large SMP machines. 64 is an arbitrary number selected to limit the worst
> of the skew without using more cache lines. min(64, NR_CPUS) is used
> instead of nr_online_cpus() because nr_online_cpus() requires a shared
> cache line and a call to hweight to make the calculation. Its runtime
> overhead and keeping this counter accurate showed up in profiles and it's
> possible that nr_online_cpus() would also show.
-- Dave
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2009-04-20 16:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-20 9:09 [PATCH V3] Fix Committed_AS underflow Eric B Munson
2009-04-20 9:18 ` KOSAKI Motohiro
2009-04-20 16:15 ` Dave Hansen [this message]
2009-04-20 19:49 ` Dave Hansen
2009-04-21 1:41 ` KOSAKI Motohiro
2009-04-23 16:31 ` Eric B Munson
2009-04-23 20:38 ` Dave Hansen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1240244120.32604.278.camel@nimitz \
--to=dave@linux.vnet.ibm.com \
--cc=cl@linux-foundation.org \
--cc=ebmunson@us.ibm.com \
--cc=kosaki.motohiro@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mel@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).