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From: Parth Shah <parth@linux.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, mingo@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	qais.yousef@arm.com, chris.hyser@oracle.com,
	patrick.bellasi@matbug.net, valentin.schneider@arm.com,
	David.Laight@ACULAB.COM, pjt@google.com, pavel@ucw.cz,
	tj@kernel.org, dhaval.giani@oracle.com, qperret@google.com,
	tim.c.chen@linux.intel.com
Subject: [PATCH v4 2/4] sched/core: Propagate parent task's latency requirements to the child task
Date: Mon, 24 Feb 2020 14:29:16 +0530	[thread overview]
Message-ID: <20200224085918.16955-3-parth@linux.ibm.com> (raw)
In-Reply-To: <20200224085918.16955-1-parth@linux.ibm.com>

Clone parent task's latency_nice attribute to the forked child task.

Reset the latency_nice value to default value when the child task is
set to sched_reset_on_fork.

Signed-off-by: Parth Shah <parth@linux.ibm.com>
Reviewed-by: Qais Yousef <qais.yousef@arm.com>
---
 kernel/sched/core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 377ec26e9159..65b6c00d6dac 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2860,6 +2860,9 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
 	 */
 	p->prio = current->normal_prio;
 
+	/* Propagate the parent's latency requirements to the child as well */
+	p->latency_nice = current->latency_nice;
+
 	uclamp_fork(p);
 
 	/*
@@ -2876,6 +2879,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
 		p->prio = p->normal_prio = __normal_prio(p);
 		set_load_weight(p, false);
 
+		p->latency_nice = DEFAULT_LATENCY_NICE;
 		/*
 		 * We don't need the reset flag anymore after the fork. It has
 		 * fulfilled its duty:
-- 
2.17.2


  parent reply	other threads:[~2020-02-24  8:59 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-24  8:59 [PATCH v4 0/4] Introduce per-task latency_nice for scheduler hints Parth Shah
2020-02-24  8:59 ` [PATCH v4 1/4] sched: Introduce latency-nice as a per-task attribute Parth Shah
2020-02-24  8:59 ` Parth Shah [this message]
2020-02-25  6:32   ` [PATCH v4 2/4] sched/core: Propagate parent task's latency requirements to the child task Pavan Kondeti
2020-02-25  8:16     ` Parth Shah
2020-02-24  8:59 ` [PATCH v4 3/4] sched: Allow sched_{get,set}attr to change latency_nice of the task Parth Shah
2020-02-25  6:54   ` Pavan Kondeti
2020-02-25 15:03     ` Parth Shah
2020-02-26  3:44       ` Pavan Kondeti
2020-02-24  8:59 ` [PATCH v4 4/4] sched/core: Add permission checks for setting the latency_nice value Parth Shah
2020-02-24 13:29   ` Qais Yousef
2020-02-25  6:47     ` Parth Shah
2020-02-27 11:44       ` Qais Yousef
2020-02-27 14:46         ` chris hyser
2020-02-24 23:08   ` chris hyser

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