releases/2.6.25.14/vfs-increase-pseudo-filesystem-block-size-to-page_size.patch

From jejb@kernel.org  Wed Jul 30 14:13:33 2008
From: Alex Nixon <alex.nixon@citrix.com>
Date: Wed, 30 Jul 2008 18:20:08 GMT
Subject: VFS: increase pseudo-filesystem block size to PAGE_SIZE
To: jejb@kernel.org, stable@kernel.org
Message-ID: <200807301820.m6UIK8W8025794@hera.kernel.org>

From: Alex Nixon <alex.nixon@citrix.com>

commit 3971e1a917548977cff71418a7c3575ffbc9571f upstream

This commit:

    commit ba52de123d454b57369f291348266d86f4b35070
    Author: Theodore Ts'o <tytso@mit.edu>
    Date:   Wed Sep 27 01:50:49 2006 -0700

        [PATCH] inode-diet: Eliminate i_blksize from the inode structure

caused the block size used by pseudo-filesystems to decrease from
PAGE_SIZE to 1024 leading to a doubling of the number of context switches
during a kernbench run.

Signed-off-by: Alex Nixon <Alex.Nixon@citrix.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/libfs.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -216,8 +216,8 @@ int get_sb_pseudo(struct file_system_typ
 
 	s->s_flags = MS_NOUSER;
 	s->s_maxbytes = ~0ULL;
-	s->s_blocksize = 1024;
-	s->s_blocksize_bits = 10;
+	s->s_blocksize = PAGE_SIZE;
+	s->s_blocksize_bits = PAGE_SHIFT;
 	s->s_magic = magic;
 	s->s_op = ops ? ops : &simple_super_operations;
 	s->s_time_gran = 1;