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From:   Mel Gorman <mgorman@techsingularity.net>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Ingo Molnar <mingo@kernel.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Aubrey Li <aubrey.li@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 1/4] sched/numa: Initialise numa_migrate_retry
Date:   Wed, 11 May 2022 15:30:35 +0100
Message-Id: <20220511143038.4620-2-mgorman@techsingularity.net>
In-Reply-To: <20220511143038.4620-1-mgorman@techsingularity.net>
References: <20220511143038.4620-1-mgorman@techsingularity.net>
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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>
---
 kernel/sched/fair.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d4bd299d67ab..867806a57119 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2873,6 +2873,7 @@ 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;
-- 
2.34.1