The patch titled
shrink struct pid by removing padding on 64 bit builds
has been added to the -mm tree. Its filename is
shrink-struct-pid-by-removing-padding-on-64-bit-builds.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: shrink struct pid by removing padding on 64 bit builds
From: Richard Kennedy <richard@xxxxxxxxxxxxxxx>
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
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pid.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN include/linux/pid.h~shrink-struct-pid-by-removing-padding-on-64-bit-builds include/linux/pid.h
--- a/include/linux/pid.h~shrink-struct-pid-by-removing-padding-on-64-bit-builds
+++ a/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];
};
_
Patches currently in -mm which might be from richard@xxxxxxxxxxxxxxx are
shrink-struct-pid-by-removing-padding-on-64-bit-builds.patch
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