[GIT PULL] scheduler fixes for v5.14

From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mel Gorman <mgorman@suse.de>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [GIT PULL] scheduler fixes for v5.14
Date: Wed, 30 Jun 2021 12:53:09 +0200	[thread overview]
Message-ID: <YNxNFX+ID+6Hqmqj@gmail.com> (raw)
In-Reply-To: <YNlxcCpk4shGcPrU@gmail.com>

Linus,

Please pull the latest sched/urgent git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-2021-06-30

   # HEAD: a22a5cb81e20657194fde6c835e07d28c4dfddbe Merge branch 'sched/core' into sched/urgent, to pick up fix

- Fix a small inconsistency (bug) in load tracking, caught by a
  new warning that several people reported.

- Flip CONFIG_SCHED_CORE to default-disabled, and update the
  Kconfig help text.

 Thanks,

	Ingo

------------------>
Ingo Molnar (1):
      sched/core: Disable CONFIG_SCHED_CORE by default

Odin Ugedal (1):
      sched/fair: Ensure _sum and _avg values stay consistent


 kernel/Kconfig.preempt | 6 +++---
 kernel/sched/fair.c    | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index bd7c4147b9a8..5876e30c5740 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -102,7 +102,6 @@ config PREEMPT_DYNAMIC
 
 config SCHED_CORE
 	bool "Core Scheduling for SMT"
-	default y
 	depends on SCHED_SMT
 	help
 	  This option permits Core Scheduling, a means of coordinated task
@@ -115,7 +114,8 @@ config SCHED_CORE
 	   - mitigation of some (not all) SMT side channels;
 	   - limiting SMT interference to improve determinism and/or performance.
 
-	  SCHED_CORE is default enabled when SCHED_SMT is enabled -- when
-	  unused there should be no impact on performance.
+	  SCHED_CORE is default disabled. When it is enabled and unused,
+	  which is the likely usage by Linux distributions, there should
+	  be no measurable impact on performance.
 
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4a3e61a88acc..45edf61eed73 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3657,15 +3657,15 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 
 		r = removed_load;
 		sub_positive(&sa->load_avg, r);
-		sub_positive(&sa->load_sum, r * divider);
+		sa->load_sum = sa->load_avg * divider;
 
 		r = removed_util;
 		sub_positive(&sa->util_avg, r);
-		sub_positive(&sa->util_sum, r * divider);
+		sa->util_sum = sa->util_avg * divider;
 
 		r = removed_runnable;
 		sub_positive(&sa->runnable_avg, r);
-		sub_positive(&sa->runnable_sum, r * divider);
+		sa->runnable_sum = sa->runnable_avg * divider;
 
 		/*
 		 * removed_runnable is the unweighted version of removed_load so we

