From: Theodore Ts'o <tytso@mit.edu>
Date: Tue, 2 Nov 2010 13:34:50 +0000 (-0400)
Subject: ext4: Remove useless spinlock in ext4_getattr()
X-Git-Tag: v2.6.37-rc2~97
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eb8abb927ae2fd1730e24ea94cd9527f3c086292;p=pandora-kernel.git

ext4: Remove useless spinlock in ext4_getattr()

Linus noted, and complained to me, that doing while lots of "git diff"'s
of kernel sources, these spinlocks were responsible for 27% of the
spinlock cost on his two-processor system as reported by perf.

Git was doing lots of parallel stats, and this was putting a lot of
pressure on ext4_getattr().  A spinlock to protect a single
memory-to-memory copy is pointless, so remove it.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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