sysctl: Make the header lists per directory.

Slightly enhance efficiency and clarity of the code by making the
header list per directory instead of per set.

Benchmark before:
    make-dummies 0 999 -> 0.63s
    rmmod dummy        -> 0.12s
    make-dummies 0 9999 -> 2m35s
    rmmod dummy         -> 18s

Benchmark after:
    make-dummies 0 999 -> 0.32s
    rmmod dummy        -> 0.12s
    make-dummies 0 9999 -> 1m17s
    rmmod dummy         -> 17s

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index cec59415b3c..36dec756ef9 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -1047,10 +1047,10 @@ struct ctl_table_header
 struct ctl_dir {
 	/* Header must be at the start of ctl_dir */
 	struct ctl_table_header header;
+	struct list_head list;
 };
 
 struct ctl_table_set {
-	struct list_head list;
 	int (*is_seen)(struct ctl_table_set *);
 	struct ctl_dir dir;
 };