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From: Frederic Weisbecker <frederic@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>,
	"Paul E . McKenney" <paulmck@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	stable@vger.kernel.org
Subject: [RFC PATCH 0/8] rcu/sched: Fix ignored rescheduling after rcu_eqs_enter() v3
Date: Sat,  9 Jan 2021 03:05:28 +0100	[thread overview]
Message-ID: <20210109020536.127953-1-frederic@kernel.org> (raw)

(This was [PATCH 0/4] sched/idle: Fix missing need_resched() checks after rcu_idle_enter() v2)

I initially followed Peterz review but eventually I tried a different
approach. Instead of handling the late wake up from rcu_idle_enter(),
I've split the delayed rcuog wake up and moved it right before
the last generic need_resched() check, it makes more sense and we don't
need to fiddle with cpuidle core and drivers anymore. It's also less
error prone.

I also fixed the nohz_full case and (hopefully) the guest case.

And this comes with debugging to prevent from that pattern to happen
again.

Only lightly tested so far.

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	sched/idle-v3

HEAD: d95fc510e804a5c4658a823ff12d9caba1d906c7

Thanks,
	Frederic
---

Frederic Weisbecker (8):
      rcu: Remove superfluous rdp fetch
      rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers
      rcu/nocb: Perform deferred wake up before last idle's need_resched() check
      rcu/nocb: Trigger self-IPI on late deferred wake up before user resume
      entry: Explicitly flush pending rcuog wakeup before last rescheduling points
      sched: Report local wake up on resched blind zone within idle loop
      entry: Report local wake up on resched blind zone while resuming to user
      timer: Report ignored local enqueue in nohz mode


 include/linux/rcupdate.h |  2 ++
 include/linux/sched.h    | 11 ++++++++
 kernel/entry/common.c    | 10 ++++++++
 kernel/rcu/tree.c        | 27 ++++++++++++++++++--
 kernel/rcu/tree.h        |  2 +-
 kernel/rcu/tree_plugin.h | 30 +++++++++++++++-------
 kernel/sched/core.c      | 66 +++++++++++++++++++++++++++++++++++++++++++++++-
 kernel/sched/idle.c      |  6 +++++
 kernel/sched/sched.h     |  3 +++
 9 files changed, 144 insertions(+), 13 deletions(-)

             reply	other threads:[~2021-01-09  2:06 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-09  2:05 Frederic Weisbecker [this message]
2021-01-09  2:05 ` [RFC PATCH 1/8] rcu: Remove superfluous rdp fetch Frederic Weisbecker
2021-01-09  9:03   ` Greg KH
2021-01-10 10:59     ` Frederic Weisbecker
2021-01-09  2:05 ` [RFC PATCH 2/8] rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers Frederic Weisbecker
2021-01-09  2:05 ` [RFC PATCH 3/8] rcu/nocb: Perform deferred wake up before last idle's need_resched() check Frederic Weisbecker
2021-01-09  2:05 ` [RFC PATCH 4/8] rcu/nocb: Trigger self-IPI on late deferred wake up before user resume Frederic Weisbecker
2021-01-11 12:04   ` Peter Zijlstra
2021-01-11 12:35     ` Frederic Weisbecker
2021-01-09  2:05 ` [RFC PATCH 5/8] entry: Explicitly flush pending rcuog wakeup before last rescheduling points Frederic Weisbecker
2021-01-11  0:40   ` Frederic Weisbecker
2021-01-11  5:13     ` Paul E. McKenney
2021-01-11 11:50       ` Frederic Weisbecker
2021-01-11 12:08   ` Peter Zijlstra
2021-01-11 12:54     ` Frederic Weisbecker
2021-01-09  2:05 ` [RFC PATCH 6/8] sched: Report local wake up on resched blind zone within idle loop Frederic Weisbecker
2021-01-11 12:25   ` Peter Zijlstra
2021-01-11 12:56     ` Frederic Weisbecker
2021-01-12  8:24   ` [sched] 9720a64438: WARNING:at_kernel/sched/core.c:#sched_resched_local_assert_allowed kernel test robot
     [not found]   ` <161062476680.19482.8402362019173198799@build.alporthouse.com>
2021-01-14 15:19     ` [RFC PATCH 6/8] sched: Report local wake up on resched blind zone within idle loop Paul E. McKenney
2021-01-09  2:05 ` [RFC PATCH 7/8] entry: Report local wake up on resched blind zone while resuming to user Frederic Weisbecker
2021-01-13  2:46   ` [entry] 8e01c5f104: unixbench.score -2.2% regression kernel test robot
2021-01-09  2:05 ` [RFC PATCH 8/8] timer: Report ignored local enqueue in nohz mode Frederic Weisbecker

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