sched/numa: Initialise numa_migrate_retry

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

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 77b2048a932622a0188f8f93680d9215559a941c..51836efe5931d8d7dd5001f3d147421f8cc4012b 100644 (file)
--- 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;