[PATCH 5.19 0291/1157] sched/numa: Initialise numa_migrate_retry

Greg Kroah-Hartman
2022-08-15T23:10:18Z

From: Mel Gorman <mgorman@techsingularity.net>

[ Upstream commit 70ce3ea9aa4ed901c8a90de667df5ef307766e71 ]

On clone, numa_migrate_retry is inherited from the parent which means
that the first NUMA placement of a task is non-deterministic. This
affects when load balancing recognises numa tasks and whether to
migrate "regular", "remote" or "all" tasks between NUMA scheduler
domains.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20220520103519.1863-2-mgorman@techsingularity.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/sched/fair.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9d6058b0a3d4..0cba1b2e295b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2885,6 +2885,7 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
p->node_stamp = 0;
p->numa_scan_seq = mm ? mm->numa_scan_seq : 0;
p->numa_scan_period = sysctl_numa_balancing_scan_delay;
+ p->numa_migrate_retry = 0;
/* Protect against double add, see task_tick_numa and task_numa_work */
p->numa_work.next = &p->numa_work;
p->numa_faults = NULL;
--
2.35.1