[mm,v2,2/3] mm: move penalty delay clamping out of calculate_high_delay()

Commit Message

Jakub Kicinski May 11, 2020, 10:55 p.m. UTC

We will want to call calculate_high_delay() twice - once for
memory and once for swap, and we should apply the clamp value
to sum of the penalties. Clamping has to be applied outside
of calculate_high_delay().

Signed-off-by: Jakub Kicinski <[e-mail]>
---
 mm/memcontrol.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Patch

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8a9b671c3249..66dd87bb9e0f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2386,14 +2386,7 @@  static unsigned long calculate_high_delay(struct mem_cgroup *memcg,
 	 * MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or
 	 * larger the current charge patch is than that.
 	 */
-	penalty_jiffies = penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH;
-
-	/*
-	 * Clamp the max delay per usermode return so as to still keep the
-	 * application moving forwards and also permit diagnostics, albeit
-	 * extremely slowly.
-	 */
-	return min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES);
+	return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH;
 }
 
 /*
@@ -2421,6 +2414,13 @@  void mem_cgroup_handle_over_high(void)
 	penalty_jiffies = calculate_high_delay(memcg, nr_pages,
 					       mem_find_max_overage(memcg));
 
+	/*
+	 * Clamp the max delay per usermode return so as to still keep the
+	 * application moving forwards and also permit diagnostics, albeit
+	 * extremely slowly.
+	 */
+	penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES);
+
 	/*
 	 * Don't sleep if the amount of jiffies this memcg owes us is so low
 	 * that it's not even worth doing, in an attempt to be nice to those who