From: Eric Sandeen <sandeen@redhat.com>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dave Jones <davej@redhat.com>,
"gnehzuil.liu" <gnehzuil.liu@gmail.com>,
Zheng Liu <wenqing.lz@taobao.com>,
"linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH] ext4: use percpu counter for extent cache count
Date: Fri, 01 Mar 2013 12:02:34 -0600 [thread overview]
Message-ID: <5130ED3A.30003@redhat.com> (raw)
In-Reply-To: <20130301180035.GB17920@thunk.org>
On 3/1/13 12:00 PM, Theodore Ts'o wrote:
> On Fri, Mar 01, 2013 at 10:42:25AM -0600, Eric Sandeen wrote:
>> Use a percpu counter rather than atomic types for shrinker accounting.
>> There's no need for ultimate accuracy in the shrinker, so this
>> should come a little more cheaply. The percpu struct is somewhat
>> large, but there was a big gap before the cache-aligned
>> s_es_lru_lock anyway, and it fits nicely in there.
>
> I thought about using percpu counters, but I was worried about the
> size on really big machines. OTOH, it will be the really large NUMA
> machines where atomic_t will really hurt, so maybe we should use
> percpu countesr and not really worry about it. It's on a per file
> system basis, so even if it is a few hundred bytes it shouldn't break
> the bank.
>
> - Ted
>
I was mostly keying off what quota felt was best, I guess.
I'm not wedded to either approach, it was just a thought.
So you can take it or leave it. :)
Thanks,
-Eric
next prev parent reply other threads:[~2013-03-01 18:02 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-26 20:39 [GIT PULL] ext4 updates for 3.9 Theodore Ts'o
2013-02-27 12:47 ` Markus Trippelsdorf
2013-02-27 15:34 ` Theodore Ts'o
2013-02-27 15:44 ` Markus Trippelsdorf
2013-02-27 17:01 ` Markus Trippelsdorf
2013-02-27 17:10 ` gnehzuil.liu
2013-02-27 17:22 ` Markus Trippelsdorf
2013-02-27 17:38 ` gnehzuil.liu
2013-02-27 17:45 ` Markus Trippelsdorf
2013-02-27 17:52 ` Linus Torvalds
2013-02-27 18:49 ` Theodore Ts'o
2013-02-27 18:56 ` Markus Trippelsdorf
2013-02-27 19:19 ` Dave Jones
2013-02-27 19:27 ` Zheng Liu
2013-02-27 19:29 ` Theodore Ts'o
2013-02-27 20:12 ` [GIT PULL URGENT] ext4 regression fix " Linus Torvalds
2013-02-27 20:15 ` Theodore Ts'o
2013-02-27 20:23 ` Linus Torvalds
2013-02-27 20:41 ` Borislav Petkov
2013-03-01 3:30 ` Dave Jones
2013-03-01 4:00 ` Theodore Ts'o
2013-03-01 5:00 ` [PATCH] ext4: optimize ext4_es_shrink() Theodore Ts'o
2013-03-01 16:11 ` Dave Jones
2013-03-01 16:26 ` Theodore Ts'o
2013-03-01 16:40 ` Dave Jones
2013-03-01 16:40 ` Eric Sandeen
2013-03-01 16:42 ` [PATCH] ext4: use percpu counter for extent cache count Eric Sandeen
2013-03-01 18:00 ` Theodore Ts'o
2013-03-01 18:02 ` Eric Sandeen [this message]
2013-03-02 15:26 ` Theodore Ts'o
2013-03-03 16:39 ` Zheng Liu
2013-03-04 16:11 ` Eric Sandeen
2013-03-02 19:54 ` [GIT PULL URGENT] ext4 regression fix for 3.9 Linus Torvalds
2013-03-02 23:15 ` Theodore Ts'o
2013-02-27 20:14 ` Theodore Ts'o
2013-02-27 20:58 ` [GIT PULL] ext4 updates " Dmitry Monakhov
2013-02-27 21:30 ` Theodore Ts'o
2013-03-01 15:41 ` Eric Sandeen
2013-02-28 13:18 ` Dave Chinner
2013-02-27 18:57 ` Dave Jones
2013-02-27 19:04 ` Theodore Ts'o
2013-02-27 19:11 ` Dave Jones
2013-02-27 19:19 ` Theodore Ts'o
2013-02-27 18:59 ` Zheng Liu
2013-02-27 19:06 ` Borislav Petkov
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