[PATCH] io: remove padding from io_context on 64bit builds

From: Richard Kennedy
Date: Fri Feb 26 2010 - 07:56:11 EST


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@xxxxxxxxxxxxxxx>

----
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;


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