linux-kernel - [PATCH 11/15] sched,fair: flatten update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190906191237.27006-12-riel@surriel.com>
Date:   Fri,  6 Sep 2019 15:12:33 -0400
From:   Rik van Riel <riel@...riel.com>
To:     linux-kernel@...r.kernel.org
Cc:     kernel-team@...com, pjt@...gle.com, dietmar.eggemann@....com,
        peterz@...radead.org, mingo@...hat.com, morten.rasmussen@....com,
        tglx@...utronix.de, mgorman@...hsingularity.net,
        vincent.guittot@...aro.org, Rik van Riel <riel@...riel.com>
Subject: [PATCH 11/15] sched,fair: flatten update_curr functionality

Make it clear that update_curr only works on tasks any more.

There is no need for task_tick_fair to call it on every sched entity up
the hierarchy, so move the call out of entity_tick.

Signed-off-by: Rik van Riel <riel@...riel.com>`
Signed-off-by: Rik van Riel <riel@...riel.com>
---
 kernel/sched/fair.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d5a3103e3d5a..5dc6d70e0df1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -888,12 +888,15 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
 static void update_curr(struct cfs_rq *cfs_rq)
 {
 	struct sched_entity *curr = cfs_rq->curr;
+	struct task_struct *curtask;
 	u64 now = rq_clock_task(rq_of(cfs_rq));
 	u64 delta_exec;
 
 	if (unlikely(!curr))
 		return;
 
+	SCHED_WARN_ON(!entity_is_task(curr));
+
 	delta_exec = now - curr->exec_start;
 	if (unlikely((s64)delta_exec <= 0))
 		return;
@@ -909,13 +912,10 @@ static void update_curr(struct cfs_rq *cfs_rq)
 	curr->vruntime += calc_delta_fair(delta_exec, curr);
 	update_min_vruntime(cfs_rq);
 
-	if (entity_is_task(curr)) {
-		struct task_struct *curtask = task_of(curr);
-
-		trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
-		cgroup_account_cputime(curtask, delta_exec);
-		account_group_exec_runtime(curtask, delta_exec);
-	}
+	curtask = task_of(curr);
+	trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
+	cgroup_account_cputime(curtask, delta_exec);
+	account_group_exec_runtime(curtask, delta_exec);
 
 	account_cfs_rq_runtime(cfs_rq, delta_exec);
 }
@@ -4212,11 +4212,6 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
 static void
 entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
 {
-	/*
-	 * Update run-time statistics of the 'current'.
-	 */
-	update_curr(cfs_rq);
-
 	/*
 	 * Ensure that runnable average is periodically updated.
 	 */
@@ -10048,6 +10043,11 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 	struct cfs_rq *cfs_rq;
 	struct sched_entity *se = &curr->se;
 
+	/*
+	 * Update run-time statistics of the 'current'.
+	 */
+	update_curr(&rq->cfs);
+
 	for_each_sched_entity(se) {
 		cfs_rq = group_cfs_rq_of_parent(se);
 		entity_tick(cfs_rq, se, queued);
-- 
2.20.1