From: Michal Hocko <mhocko@suse.cz>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] page_cgroup: Reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM
Date: Thu, 24 Feb 2011 10:35:19 +0100 [thread overview]
Message-ID: <20110224093519.GB20922@tiehlicka.suse.cz> (raw)
In-Reply-To: <20110224085227.1a3e185b.kamezawa.hiroyu@jp.fujitsu.com>
On Thu 24-02-11 08:52:27, KAMEZAWA Hiroyuki wrote:
> On Wed, 23 Feb 2011 10:19:22 -0800
> Dave Hansen <dave@linux.vnet.ibm.com> wrote:
>
> > On Wed, 2011-02-23 at 16:10 +0100, Michal Hocko wrote:
> > > We can reduce this internal fragmentation by splitting the single
> > > page_cgroup array into more arrays where each one is well kmalloc
> > > aligned. This patch implements this idea.
> >
> > How about using alloc_pages_exact()? These things aren't allocated
> > often enough to really get most of the benefits of being in a slab.
> > That'll at least get you down to a maximum of about PAGE_SIZE wasted.
> >
>
> yes, alloc_pages_exact() is much better.
>
> packing page_cgroups for multiple sections causes breakage in memory hotplug logic.
I am not sure I understand this. What do you mean by packing
page_cgroups for multiple sections? The patch I have posted doesn't do
any packing. Or do you mean that using a double array can break hotplog?
Not that this would change anything, alloc_pages_exact is really a
better solution, I am just curious ;)
--
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-02-24 9:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-23 15:10 Michal Hocko
2011-02-23 18:19 ` Dave Hansen
2011-02-23 23:52 ` KAMEZAWA Hiroyuki
2011-02-24 9:35 ` Michal Hocko [this message]
2011-02-24 10:02 ` KAMEZAWA Hiroyuki
2011-02-24 9:33 ` Michal Hocko
2011-02-24 13:40 ` [RFC PATCH] page_cgroup: Reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM v2 Michal Hocko
2011-02-25 3:25 ` KAMEZAWA Hiroyuki
2011-02-25 9:53 ` [RFC PATCH] page_cgroup: Reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM v3 Michal Hocko
2011-02-28 0:53 ` KAMEZAWA Hiroyuki
2011-02-28 9:12 ` [RFC PATCH] page_cgroup: Reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM v4 Michal Hocko
2011-02-28 9:23 ` KAMEZAWA Hiroyuki
2011-02-28 9:53 ` Michal Hocko
2011-02-28 9:48 ` KAMEZAWA Hiroyuki
2011-02-28 10:12 ` Michal Hocko
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=20110224093519.GB20922@tiehlicka.suse.cz \
--to=mhocko@suse.cz \
--cc=dave@linux.vnet.ibm.com \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.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