module: reorder kparam_array to remove alignment padding on 64 bit builds
Richard Kennedy [Thu, 19 May 2011 22:55:25 +0000 (16:55 -0600)]
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>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

include/linux/moduleparam.h

index 07b4195..ddaae98 100644 (file)
@@ -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, &param_ops_##type,                 \
-           sizeof(array[0]), array };                                  \
+       = { .max = ARRAY_SIZE(array), .num = nump,                      \
+           .ops = &param_ops_##type,                                   \
+           .elemsize = sizeof(array[0]), .elem = array };              \
        __module_param_call(MODULE_PARAM_PREFIX, name,                  \
                            &param_array_ops,                           \
                            .arr = &__param_arr_##name,                 \