linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Nathan Zimmer <nzimmer@sgi.com>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	adobriyan@gmail.com, Alexander Viro <viro@zeniv.linux.org.uk>,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] fs/proc: Move kfree outside pde_unload_lock
Date: Fri, 24 Aug 2012 16:58:31 +0200	[thread overview]
Message-ID: <1345820311.4824.2.camel@edumazet-laptop> (raw)
In-Reply-To: <20120824144852.GA18850@gulag1.americas.sgi.com>

Le vendredi 24 août 2012 à 09:48 -0500, Nathan Zimmer a écrit :
> On Wed, Aug 22, 2012 at 11:42:58PM +0200, Eric Dumazet wrote:
> > On Wed, 2012-08-22 at 20:28 +0200, Eric Dumazet wrote:
> > 
> > > 
> > > Thats interesting, but if you really want this to fly, one RCU
> > > conversion would be much better ;)
> > > 
> > > pde_users would be an atomic_t and you would avoid the spinlock
> > > contention.
> > 
> > Here is what I had in mind, I would be interested to know how it helps a 512 core machine ;)
> > 
> 
> Here are the results and they look great.
> 
> cpuinfo	baseline	moved kfree	Rcu 
> tasks	read-sec	read-sec	read-sec
> 1	0.0141		0.0141		0.0141
> 2	0.0140		0.0140		0.0142
> 4	0.0140		0.0141		0.0141
> 8	0.0145		0.0145		0.0140
> 16	0.0553		0.0548		0.0168
> 32	0.1688		0.1622		0.0549
> 64	0.5017		0.3856		0.1690
> 128	1.7005		0.9710		0.5038
> 256	5.2513		2.6519		2.0804
> 512	8.0529		6.2976		3.0162
> 
> 
> 

Indeed...

Could you explicit the test you are actually doing ?

Thanks



  reply	other threads:[~2012-08-24 14:58 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-22 16:38 [PATCH] fs/proc: Move kfree outside pde_unload_lock Nathan Zimmer
2012-08-22 16:38 ` [PATCH] fs/prof: Update comment on pde_unload_lock Nathan Zimmer
2012-08-22 18:28 ` [PATCH] fs/proc: Move kfree outside pde_unload_lock Eric Dumazet
2012-08-22 21:42   ` Eric Dumazet
2012-08-23 17:54     ` Nathan Zimmer
2012-08-24 14:48     ` Nathan Zimmer
2012-08-24 14:58       ` Eric Dumazet [this message]
2012-08-24 16:45         ` Nathan Zimmer
2012-08-24 21:43           ` Nathan Zimmer
2012-08-28 20:38     ` Alexey Dobriyan
2012-08-29  4:11       ` Eric Dumazet
2012-08-29  8:32         ` Alexey Dobriyan
2012-08-29 13:50         ` Alexey Dobriyan
2012-08-29 14:24           ` Eric Dumazet
2012-09-17 15:57             ` Nathan Zimmer

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=1345820311.4824.2.camel@edumazet-laptop \
    --to=eric.dumazet@gmail.com \
    --cc=adobriyan@gmail.com \
    --cc=dwmw2@infradead.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nzimmer@sgi.com \
    --cc=viro@zeniv.linux.org.uk \
    /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).