[PATCH v2 14/19] sched/numa: Updation of scan period need not be in lock

From: Srikar Dronamraju
Date: Wed Jun 20 2018 - 13:04:09 EST


The metrics for updating scan periods are local or task specific.
Currently this updation happens under numa_group lock which seems
unnecessary. Hence move this updation outside the lock.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS LAST_PATCH WITH_PATCH %CHANGE
16 25355.9 25645.4 1.141
1 72812 72142 -0.92

Reviewed-by: Rik van Riel <riel@xxxxxxxxxxx>
Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
kernel/sched/fair.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 10b6886..711b533 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2162,8 +2162,6 @@ static void task_numa_placement(struct task_struct *p)
}
}

- update_task_scan_period(p, fault_types[0], fault_types[1]);
-
if (p->numa_group) {
numa_group_count_active_nodes(p->numa_group);
spin_unlock_irq(group_lock);
@@ -2178,6 +2176,8 @@ static void task_numa_placement(struct task_struct *p)
if (task_node(p) != p->numa_preferred_nid)
numa_migrate_preferred(p);
}
+
+ update_task_scan_period(p, fault_types[0], fault_types[1]);
}

static inline int get_numa_group(struct numa_group *grp)
--
1.8.3.1