fs: Don't need to put list_lru into its own cacheline

The list_lru structure is essentially just a pointer to a table of
per-node LRU lists.  Even if CONFIG_MEMCG_KMEM is defined, the list
field is just used for LRU list registration and shrinker_id is set at
initialization.  Those fields won't need to be touched that often.

So there is no point to make the list_lru structures to sit in their own
cachelines.

Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 811c77743dad2870282e6c3c85e8f238f8643767..29d8e2cfed0e7b87240a0130fbb00edcb9bc8984 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1479,11 +1479,12 @@ struct super_block {
        struct user_namespace *s_user_ns;
 
        /*
-        * Keep the lru lists last in the structure so they always sit on their
-        * own individual cachelines.
+        * The list_lru structure is essentially just a pointer to a table
+        * of per-node lru lists, each of which has its own spinlock.
+        * There is no need to put them into separate cachelines.
         */
-       struct list_lru         s_dentry_lru ____cacheline_aligned_in_smp;
-       struct list_lru         s_inode_lru ____cacheline_aligned_in_smp;
+       struct list_lru         s_dentry_lru;
+       struct list_lru         s_inode_lru;
        struct rcu_head         rcu;
        struct work_struct      destroy_work;