From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Matt Mackall <mpm@selenic.com>, Paul Menage <menage@google.com>,
Randy Dunlap <randy.dunlap@oracle.com>,
linux-kernel@vger.kernel.org
Subject: Re: [patch -mm] cpusets: add memory_slab_hardwall flag
Date: Wed, 11 Mar 2009 18:03:30 -0700 [thread overview]
Message-ID: <20090312010330.GK7086@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.1.10.0903091448110.20314@qirst.com>
On Mon, Mar 09, 2009 at 02:50:06PM -0400, Christoph Lameter wrote:
> Again these are fastpath modifications.
>
> Scanning the partial list for matching nodes is an expensive operation.
>
> Adding RCU into the fast paths is also another big worry.
Hello, Christoph,
Adding synchronize_rcu() into a fast path would certainly be a problem,
but call_rcu() should be OK. If the data structure is updated often
(old elements removed and new elements added), then the cache misses
from elements that were removed, went cache-cold, and then were added
again could potentially cause trouble, but read-mostly data structures
should be OK.
Or were you worried about some other aspect of RCU overhead?
Thanx, Paul
next prev parent reply other threads:[~2009-03-12 1:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-08 16:27 [patch -mm] cpusets: add memory_slab_hardwall flag David Rientjes
2009-03-08 16:53 ` Paul Menage
2009-03-08 21:38 ` David Rientjes
2009-03-09 7:08 ` Paul Menage
2009-03-09 9:18 ` David Rientjes
2009-03-08 17:01 ` Matt Mackall
2009-03-08 21:51 ` David Rientjes
2009-03-09 4:49 ` KOSAKI Motohiro
2009-03-09 9:12 ` David Rientjes
2009-03-09 10:19 ` KOSAKI Motohiro
2009-03-09 20:26 ` David Rientjes
2009-03-09 21:14 ` Christoph Lameter
2009-03-09 21:31 ` David Rientjes
2009-03-10 20:50 ` Christoph Lameter
2009-03-10 21:08 ` Matt Mackall
2009-03-12 16:08 ` Christoph Lameter
2009-03-12 17:23 ` Matt Mackall
2009-03-10 22:12 ` Paul Menage
2009-03-12 15:51 ` Christoph Lameter
2009-03-09 18:50 ` Christoph Lameter
2009-03-09 20:13 ` David Rientjes
2009-03-10 1:35 ` KOSAKI Motohiro
2009-03-10 2:01 ` David Rientjes
2009-03-10 4:05 ` Matt Mackall
2009-03-10 4:26 ` David Rientjes
2009-03-12 1:03 ` Paul E. McKenney [this message]
2009-03-12 5:51 ` David Rientjes
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=20090312010330.GK7086@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=menage@google.com \
--cc=mpm@selenic.com \
--cc=penberg@cs.helsinki.fi \
--cc=randy.dunlap@oracle.com \
--cc=rientjes@google.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