[RFC PATCH v4 13/16] mm/mglru: remove redundant gens <= MIN_NR_GENS check in should_run_aging()

["Barry Song (Xiaomi)" <baohua@kernel.org>]

From: Bo Zhang <zhangbo56@xiaomi.com>

If the following condition is true,

        if (min_seq[type] + MIN_NR_GENS > max_seq)
                return true;

then this one must also be true,

        if (evictable_min_seq(min_seq, swappiness) + MIN_NR_GENS > max_seq)
                return true;

The converse is not true, so the evictable_min_seq() check is
redundant and can be removed.

Signed-off-by: Bo Zhang <zhangbo56@xiaomi.com>
Signed-off-by: Barry Song (Xiaomi) <baohua@kernel.org>
---
 mm/vmscan.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 50f0bcf9576c..a276560bc66b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -5098,10 +5098,6 @@ static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq,
 	int type = get_type_to_scan(lruvec, swappiness);
 	DEFINE_MIN_SEQ(lruvec);
 
-	/* have to run aging, since eviction is not possible anymore */
-	if (evictable_min_seq(min_seq, swappiness) + MIN_NR_GENS > max_seq)
-		return true;
-
 	/* run aging if the preferred type is exhausted */
 	if (min_seq[type] + MIN_NR_GENS > max_seq)
 		return true;
-- 
2.34.1