On Thu, 28 Apr 2022 15:00:11 -0300 Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote:
On Thu, Mar 31, 2022 at 03:52:45PM +0200, Borislav Petkov wrote:I guess not.
On Thu, Mar 10, 2022 at 10:22:12AM -0300, Marcelo Tosatti wrote:...
Someone pointed me at this:Michael,
https://www.phoronix.com/scan.php?page=news_item&px=Linux-518-Stress-NUMA-Goes-Boom
which says this one causes a performance regression with stress-ng's
NUMA test...
This is probably do_migrate_pages that is taking too long due to
synchronize_rcu().
Switching to synchronize_rcu_expedited() should probably fix it...
Can you give it a try, please?
Is anyone else able to demonstrate a stress-ng performance regression
due to ff042f4a9b0508? And if so, are they able to try Marcelo's
one-liner?
diff --git a/mm/swap.c b/mm/swap.c
index bceff0cb559c..04a8bbf9817a 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -879,7 +879,7 @@ 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