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authorRichard Kennedy <richard@rsk.demon.co.uk>2008-07-25 01:48:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:45 -0700
commit33166b1ffca5e1945246bcaa77d72a22b0d3e531 (patch)
tree5e949f9f68c93ad4a487aa84aa959a5658cfd321 /include
parent3ae4eed34be0177a8e003411a84e4ee212adbced (diff)
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shrink struct pid by removing padding on 64 bit builds
When struct pid is built on a 64 bit platform gcc has to insert padding to maintain the correct alignment, by simply reordering its members the memory usage shrinks from 88 bytes to 80. I've successfully run with this patch on my desktop AMD64 machine. There are no significant kernel size changes to a default config.X86_64 on the latest git v2.6.26-rc1 text data bss dec hex filename 5404828 976760 734280 7115868 6c945c vmlinux 5404811 976760 734280 7115851 6c944b vmlinux.pid-patch Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/pid.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/pid.h b/include/linux/pid.h
index c21c7e8124a..6f084b9e2c4 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -57,10 +57,10 @@ struct upid {
struct pid
{
atomic_t count;
+ unsigned int level;
/* lists of tasks that use this pid */
struct hlist_head tasks[PIDTYPE_MAX];
struct rcu_head rcu;
- unsigned int level;
struct upid numbers[1];
};