mm: lru_cache_disable: use synchronize_rcu_expedited

commit ff042f4 ("mm: lru_cache_disable: replace work queue
synchronization with synchronize_rcu") replaced lru_cache_disable's usage
of work queues with synchronize_rcu.

Some users reported large performance regressions due to this commit, for
example:
https://lore.kernel.org/all/20220521234616.GO1790663@paulmck-ThinkPad-P17-Gen-1/T/

Switching to synchronize_rcu_expedited fixes the problem.

Link: https://lkml.kernel.org/r/YpToHCmnx/[email protected]
Fixes: ff042f4 ("mm: lru_cache_disable: replace work queue synchronization with synchronize_rcu")
Signed-off-by: Marcelo Tosatti <[email protected]>
Tested-by: Stefan Wahren <[email protected]>
Tested-by: Michael Larabel <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Nicolas Saenz Julienne <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Phil Elwell <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: matosatti

mm/swap.c

@@ -881,7 +881,7 @@ void lru_cache_disable(void)
 	 * lru_disable_count = 0 will have exited the critical
 	 * section when synchronize_rcu() returns.
 	 */
-	synchronize_rcu();
+	synchronize_rcu_expedited();
 #ifdef CONFIG_SMP
 	__lru_add_drain_all(true);
 #else