linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mel Gorman <mel@csn.ul.ie>
To: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>,
	Minchan Kim <minchan.kim@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Bob Liu <lliubbo@gmail.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 2/6] change alloc function in pcpu_alloc_pages
Date: Tue, 20 Apr 2010 16:05:22 +0100	[thread overview]
Message-ID: <20100420150522.GG19264@csn.ul.ie> (raw)
In-Reply-To: <4BCCD8BD.1020307@kernel.org>

On Tue, Apr 20, 2010 at 07:27:09AM +0900, Tejun Heo wrote:
> Hello, Christoph.
> 
> On 04/20/2010 02:38 AM, Christoph Lameter wrote:
> > alloc_pages_exact_node results in more confusion because it does suggest
> > that fallback to other nodes is not allowed.
> 
> I can't see why alloc_pages_exact_node() exists at all.  It's in the
> mainline and if you look at the difference between alloc_pages_node()
> and alloc_pages_exact_node(), it's almost silly.  :-(
> 

alloc_pages_exact_node() avoids a branch in a hot path that is checking for
something the caller already knows. That's the reason it exists.

-- 
Mel Gorman
Part-time Phd Student                          Linux Technology Center
University of Limerick                         IBM Dublin Software Lab

  reply	other threads:[~2010-04-20 15:05 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-13 15:24 [PATCH 1/6] Remove node's validity check in alloc_pages Minchan Kim
2010-04-13 15:24 ` [PATCH 2/6] change alloc function in pcpu_alloc_pages Minchan Kim
2010-04-13 15:48   ` Mel Gorman
2010-04-14 23:39     ` Tejun Heo
2010-04-15  1:31       ` Minchan Kim
2010-04-15  7:21         ` Tejun Heo
2010-04-15  8:00           ` Minchan Kim
2010-04-15  8:15             ` Tejun Heo
2010-04-15  9:40               ` Minchan Kim
2010-04-15 10:08                 ` Tejun Heo
2010-04-15 10:21                   ` Minchan Kim
2010-04-15 10:33                     ` Minchan Kim
2010-04-15 11:43                     ` Tejun Heo
2010-04-15 11:49                       ` Minchan Kim
2010-04-16 16:07                         ` Christoph Lameter
2010-04-16 19:13                           ` Lee Schermerhorn
2010-04-18 15:55                             ` Minchan Kim
2010-04-18 15:54                           ` Minchan Kim
2010-04-18 21:22                             ` Tejun Heo
2010-04-19  0:03                               ` Minchan Kim
2010-04-19 17:45                                 ` Christoph Lameter
2010-04-20  0:20                                   ` Minchan Kim
2010-04-19 17:38                             ` Christoph Lameter
2010-04-19 22:27                               ` Tejun Heo
2010-04-20 15:05                                 ` Mel Gorman [this message]
2010-04-21 10:48                                   ` Tejun Heo
2010-04-22 10:15                                     ` Minchan Kim
2010-04-21 14:15                                   ` Christoph Lameter
2010-04-21 17:06                                     ` Minchan Kim
2010-04-13 15:25 ` [PATCH 3/6] change alloc function in alloc_slab_page Minchan Kim
2010-04-13 15:52   ` Mel Gorman
2010-04-13 16:01     ` Minchan Kim
2010-04-13 16:14       ` Mel Gorman
2010-04-13 21:37   ` David Rientjes
2010-04-13 23:40     ` Minchan Kim
2010-04-13 23:55       ` David Rientjes
2010-04-14  0:02         ` Minchan Kim
2010-04-14  0:18   ` KAMEZAWA Hiroyuki
2010-04-14 12:23     ` Pekka Enberg
2010-04-16 16:10       ` Christoph Lameter
2010-04-18 18:49         ` Pekka Enberg
2010-04-19  9:05         ` Mel Gorman
2010-04-13 15:25 ` [PATCH 4/6] change alloc function in vmemmap_alloc_block Minchan Kim
2010-04-13 15:59   ` Mel Gorman
2010-04-14  0:19   ` KAMEZAWA Hiroyuki
2010-04-13 15:25 ` [PATCH 5/6] change alloc function in __vmalloc_area_node Minchan Kim
2010-04-13 16:02   ` Mel Gorman
2010-04-14  0:22   ` KAMEZAWA Hiroyuki
2010-04-14  0:33     ` Minchan Kim
2010-04-13 15:25 ` [PATCH 6/6] Add comment in alloc_pages_exact_node Minchan Kim
2010-04-13 16:13   ` Mel Gorman
2010-04-13 16:20     ` Minchan Kim
2010-04-13 15:32 ` [PATCH 1/6] Remove node's validity check in alloc_pages Mel Gorman
2010-04-14  0:04 ` KAMEZAWA Hiroyuki

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=20100420150522.GG19264@csn.ul.ie \
    --to=mel@csn.ul.ie \
    --cc=akpm@linux-foundation.org \
    --cc=cl@linux-foundation.org \
    --cc=kamezawa.hiroyu@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lliubbo@gmail.com \
    --cc=minchan.kim@gmail.com \
    --cc=tj@kernel.org \
    /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).