From: Richard Kennedy <richard@rsk.demon.co.uk>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] module: reorder kparam_array to remove alignment padding on 64 bit builds
Date: Wed, 23 Feb 2011 17:14:56 +0000 [thread overview]
Message-ID: <1298481296.2130.7.camel@castor.rsk> (raw)
Reorder structure kparam_array to remove 8 bytes of alignment padding on
64 bit builds, dropping its size from 40 to 32 bytes.
Also update the macro module_param_array_named to initialise the
structure using its member names to allow it to be changed without
touching all its call sites.
'git grep' finds module_param_array in 1037 places so this patch will
save a small amount of data space across many modules.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against v2.6.38-rc6
compiled & tested on x86_64
regards
Richard
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 07b4195..ddaae98 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -67,9 +67,9 @@ struct kparam_string {
struct kparam_array
{
unsigned int max;
+ unsigned int elemsize;
unsigned int *num;
const struct kernel_param_ops *ops;
- unsigned int elemsize;
void *elem;
};
@@ -371,8 +371,9 @@ extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
*/
#define module_param_array_named(name, array, type, nump, perm) \
static const struct kparam_array __param_arr_##name \
- = { ARRAY_SIZE(array), nump, ¶m_ops_##type, \
- sizeof(array[0]), array }; \
+ = { .max = ARRAY_SIZE(array), .num = nump, \
+ .ops = ¶m_ops_##type, \
+ .elemsize = sizeof(array[0]), .elem = array }; \
__module_param_call(MODULE_PARAM_PREFIX, name, \
¶m_array_ops, \
.arr = &__param_arr_##name, \
reply other threads:[~2011-02-23 17:15 UTC|newest]
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