linux-kernel - [RFC PATCH] Remove redundant sched_numa

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Message-Id: <20210118103218.204373-1-imran.f.khan@oracle.com>
Date:   Mon, 18 Jan 2021 21:32:18 +1100
From:   Imran Khan <imran.f.khan@...cle.com>
To:     mingo@...hat.com, peterz@...radead.org, vincent.guittot@...aro.org
Cc:     juri.lelli@...hat.com, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, linux-kernel@...r.kernel.org
Subject: [RFC PATCH] Remove redundant sched_numa_balancing check.

task_numa_fault is invoked from do_numa_page/do_huge_pmd_numa_page,
for task_numa_work induced memory faults. task_numa_work is scheduled
from task_tick_numa which is invoked only if sched_numa_balancing
is true.

So task_numa_fault will not get invoked if sched_numa_balancing is
false and hence we can avoid checking it again in task_numa_fault.

Signed-off-by: Imran Khan <imran.f.khan@...cle.com>
---
 kernel/sched/fair.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 04a3ce20da67..282ebd6c4197 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2643,9 +2643,6 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
 	struct numa_group *ng;
 	int priv;
 
-	if (!static_branch_likely(&sched_numa_balancing))
-		return;
-
 	/* for example, ksmd faulting in a user's mm */
 	if (!p->mm)
 		return;
-- 
2.25.1