From: Dave Jones <davej@redhat.com>
Subject: Re: [PATCH] ext4: optimize ext4_es_shrink()
Date: Fri, 1 Mar 2013 11:11:30 -0500
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Cc: "gnehzuil.liu" <gnehzuil.liu@gmail.com>,
	Zheng Liu <wenqing.lz@taobao.com>,
	"linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>
To: "Theodore Ts'o" <tytso@mit.edu>
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On Fri, Mar 01, 2013 at 12:00:29AM -0500, Theodore Ts'o wrote:
 > When the system is under memory pressure, ext4_es_srhink() will get
 > called very often.  So optimize returning the number of items in the
 > file system's extent status cache by keeping a per-filesystem count,
 > instead of calculating it each time by scanning all of the inodes in
 > the extent status cache.
 > 
 > Also rename the slab used for the extent status cache to be
 > "ext4_extent_status" so it's obviousl the slab in question is created
 > by ext4.

Seems to work with no ill effects afaics.

thanks,

	Dave