If reclaim fails to make sufficient progress, the priority is raised.Perhaps better named "kswapd_skip_congestion_wait" ?
Once the priority is higher, kswapd starts waiting on congestion. However,
if the zone is below the min watermark then kswapd needs to continue working
without delay as there is a danger of an increased rate of GFP_ATOMIC
allocation failure.
This patch changes the conditions under which kswapd waits on
congestion by only going to sleep if the min watermarks are being met.
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 90b11e4..bc09547 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -685,6 +685,7 @@ static const char * const vmstat_text[] = {
"kswapd_inodesteal",
"kswapd_slept_prematurely_fast",
"kswapd_slept_prematurely_slow",
+ "kswapd_no_congestion_wait",