linux-kernel - [GIT PULL v2] scheduler fixes

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Message-ID: <20191117104112.GB56088@gmail.com>
Date:   Sun, 17 Nov 2019 11:41:12 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Valentin Schneider <valentin.schneider@....com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>,
        Thomas Gleixner <tglx@...utronix.de>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL v2] scheduler fixes


* Linus Torvalds <torvalds@...ux-foundation.org> wrote:

> On Sat, Nov 16, 2019 at 2:44 PM Valentin Schneider
> <valentin.schneider@....com> wrote:
> >
> > > Valentin Schneider (2):
> > >       sched/uclamp: Fix overzealous type replacement
> >
> > This one got a v2 (was missing one location), acked by Vincent:
> >
> >   20191115103908.27610-1-valentin.schneider@....com
> >
> > >       sched/topology, cpuset: Account for housekeeping CPUs to avoid empty cpumasks
> >
> > And this one is no longer needed, as Michal & I understood (IOW the fix in
> > rc6 is sufficient), see:
> >
> >   c425c5cb-ba8a-e5f6-d91c-5479779cfb7a@....com
> 
> Ingo, what do you want me to do? Pull it anyway and send updates
> later? Or skip this pull request?
> 
> I'll leave it pending for now,

We ended up zapping the final two commits from sched/urgent.

Please pull the latest sched-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus

   # HEAD: 6e1ff0773f49c7d38e8b4a9df598def6afb9f415 sched/uclamp: Fix incorrect condition

Misc fixes:

 - Fix potential deadlock under CONFIG_DEBUG_OBJECTS=y
 - PELT metrics update ordering fix
 - uclamp logic fix

 Thanks,

	Ingo

------------------>
Peter Zijlstra (1):
      sched/core: Avoid spurious lock dependencies

Qais Yousef (1):
      sched/uclamp: Fix incorrect condition

Vincent Guittot (1):
      sched/pelt: Fix update of blocked PELT ordering


 kernel/sched/core.c |  5 +++--
 kernel/sched/fair.c | 29 ++++++++++++++++++++---------
 2 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0f2eb3629070..44123b4d14e8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1065,7 +1065,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
 	 * affecting a valid clamp bucket, the next time it's enqueued,
 	 * it will already see the updated clamp bucket value.
 	 */
-	if (!p->uclamp[clamp_id].active) {
+	if (p->uclamp[clamp_id].active) {
 		uclamp_rq_dec_id(rq, p, clamp_id);
 		uclamp_rq_inc_id(rq, p, clamp_id);
 	}
@@ -6019,10 +6019,11 @@ void init_idle(struct task_struct *idle, int cpu)
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long flags;
 
+	__sched_fork(0, idle);
+
 	raw_spin_lock_irqsave(&idle->pi_lock, flags);
 	raw_spin_lock(&rq->lock);
 
-	__sched_fork(0, idle);
 	idle->state = TASK_RUNNING;
 	idle->se.exec_start = sched_clock();
 	idle->flags |= PF_IDLE;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 22a2fed29054..69a81a5709ff 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7547,6 +7547,19 @@ static void update_blocked_averages(int cpu)
 	rq_lock_irqsave(rq, &rf);
 	update_rq_clock(rq);
 
+	/*
+	 * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure
+	 * that RT, DL and IRQ signals have been updated before updating CFS.
+	 */
+	curr_class = rq->curr->sched_class;
+	update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
+	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
+	update_irq_load_avg(rq, 0);
+
+	/* Don't need periodic decay once load/util_avg are null */
+	if (others_have_blocked(rq))
+		done = false;
+
 	/*
 	 * Iterates the task_group tree in a bottom up fashion, see
 	 * list_add_leaf_cfs_rq() for details.
@@ -7574,14 +7587,6 @@ static void update_blocked_averages(int cpu)
 			done = false;
 	}
 
-	curr_class = rq->curr->sched_class;
-	update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
-	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
-	update_irq_load_avg(rq, 0);
-	/* Don't need periodic decay once load/util_avg are null */
-	if (others_have_blocked(rq))
-		done = false;
-
 	update_blocked_load_status(rq, !done);
 	rq_unlock_irqrestore(rq, &rf);
 }
@@ -7642,12 +7647,18 @@ static inline void update_blocked_averages(int cpu)
 
 	rq_lock_irqsave(rq, &rf);
 	update_rq_clock(rq);
-	update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq);
 
+	/*
+	 * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure
+	 * that RT, DL and IRQ signals have been updated before updating CFS.
+	 */
 	curr_class = rq->curr->sched_class;
 	update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
 	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
 	update_irq_load_avg(rq, 0);
+
+	update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq);
+
 	update_blocked_load_status(rq, cfs_rq_has_blocked(cfs_rq) || others_have_blocked(rq));
 	rq_unlock_irqrestore(rq, &rf);
 }