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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.