From: Richard Kennedy <richard@rsk.demon.co.uk>
To: Jens Axboe <jens.axboe@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nikanth Karthikesan <knikanth@suse.de>,
Jeff Moyer <jmoyer@redhat.com>, Vivek Goyal <vgoyal@redhat.com>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] io: remove padding from io_context on 64bit builds
Date: Fri, 26 Feb 2010 12:56:00 +0000 [thread overview]
Message-ID: <1267188960.2077.10.camel@localhost> (raw)
On 64 bit builds when CONFIG_BLK_CGROUP=n (the default) this removes 8
bytes of padding from structure io_context and drops its size from 72 to
64 bytes, so needing one fewer cachelines and allowing more objects per
slab in it's kmem_cache.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against 2.6.33
compiled & test on x86_64 AMDX2
regards
Richard
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index 78ef023..1195a80 100644
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -49,8 +49,8 @@ struct io_context {
/*
* For request batching
*/
- unsigned long last_waited; /* Time last woken after wait for request */
int nr_batch_requests; /* Number of requests left in the batch */
+ unsigned long last_waited; /* Time last woken after wait for request */
struct radix_tree_root radix_root;
struct hlist_head cic_list;
next reply other threads:[~2010-02-26 12:56 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-26 12:56 Richard Kennedy [this message]
2010-02-26 13:01 ` [PATCH] io: remove padding from io_context on 64bit builds Jens Axboe
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