Revert "memcg: enable accounting for file lock caches"

This reverts commit 0f12156.

The kernel test robot reports a sizeable performance regression for this
commit, and while it clearly does the rigth thing in theory, we'll need
to look at just how to avoid or minimize the performance overhead of the
memcg accounting.

People already have suggestions on how to do that, but it's "future
work".

So revert it for now.

Link: https://lore.kernel.org/lkml/20210907150757.GE17617@xsang-OptiPlex-9020/
Acked-by: Jens Axboe <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

fs/locks.c

@@ -2941,12 +2941,10 @@ static int __init filelock_init(void)
 	int i;
 
 	flctx_cache = kmem_cache_create("file_lock_ctx",
-			sizeof(struct file_lock_context), 0,
-			SLAB_PANIC | SLAB_ACCOUNT, NULL);
+			sizeof(struct file_lock_context), 0, SLAB_PANIC, NULL);
 
 	filelock_cache = kmem_cache_create("file_lock_cache",
-			sizeof(struct file_lock), 0,
-			SLAB_PANIC | SLAB_ACCOUNT, NULL);
+			sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
 
 	for_each_possible_cpu(i) {
 		struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i);