2008-12-04 11:18:00

by Richard Kennedy

[permalink] [raw]
Subject: [PATCH] fs: reorder struct inotify_device on 64bits to remove padding

Reorder struct inotify_device to remove 8 bytes of padding on 64bit
builds, reducing size to 128 bytes . Therefore allocating from a smaller
slab & using one fewer cachelines.

Signed-off-by: Richard Kennedy <[email protected]>

----
Hi,
patch against 2.6.28-rc7.
built & tested on AMDX2 desktop.

I've not been able to send this to the listed inotify maintainers, I
just get mail failures. So I guessed filesystem was the best home for
it, hope that's ok.

regards
Richard


diff --git a/fs/inotify_user.c b/fs/inotify_user.c
index d367e9b..5554d7f 100644
--- a/fs/inotify_user.c
+++ b/fs/inotify_user.c
@@ -76,10 +76,10 @@ struct inotify_device {
struct mutex ev_mutex; /* protects event queue */
struct mutex up_mutex; /* synchronizes watch updates */
struct list_head events; /* list of queued events */
- atomic_t count; /* reference count */
struct user_struct *user; /* user who opened this dev */
struct inotify_handle *ih; /* inotify handle */
struct fasync_struct *fa; /* async notification */
+ atomic_t count; /* reference count */
unsigned int queue_size; /* size of the queue (bytes) */
unsigned int event_count; /* number of pending events */
unsigned int max_events; /* maximum number of events */