From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [patch 0/5] sched: Miscellaneous RT related tweaks
Date: Tue, 28 Sep 2021 14:24:23 +0200 (CEST) [thread overview]
Message-ID: <20210928122339.502270600@linutronix.de> (raw)
RT enabled kernels have a few issues with the inner workings of the
scheduler:
- The remote TTWU_QUEUE mechanism leads to 5x larger maximum latencies
- The batched migration limit of 32 tasks causes large latencies
- The cleanup of kprobes, vmapped stacks of dead tasks and mmdrop() are
latency sources and eventually calling into code pathes which take
regular spinlocks from within the scheduler core which has preemption
disabled.
The following series cleans this up. It is also available from git:
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git sched
applied on top of the previous might_sleep() cleanups:
https://lore.kernel.org/r/20210923164145.466686140@linutronix.de
Thanks,
tglx
---
include/linux/mm_types.h | 4 ++++
include/linux/sched/mm.h | 20 ++++++++++++++++++++
kernel/exit.c | 7 +++++++
kernel/fork.c | 18 +++++++++++++++++-
kernel/kprobes.c | 8 ++++----
kernel/sched/core.c | 16 +++++++++-------
kernel/sched/features.h | 5 +++++
7 files changed, 66 insertions(+), 12 deletions(-)
next reply other threads:[~2021-09-28 12:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-28 12:24 Thomas Gleixner [this message]
2021-09-28 12:24 ` [patch 1/5] sched: Limit the number of task migrations per batch on RT Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 2/5] sched: Disable TTWU_QUEUE " Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 3/5] sched: Move kprobes cleanup out of finish_task_switch() Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
2021-09-28 12:24 ` [patch 4/5] sched: Delay task stack freeing on RT Thomas Gleixner
2021-09-29 11:54 ` Peter Zijlstra
2021-10-01 16:12 ` Andy Lutomirski
2021-10-01 17:24 ` Thomas Gleixner
2021-10-01 18:48 ` Andy Lutomirski
2021-10-01 19:02 ` Andy Lutomirski
2021-10-01 20:54 ` Thomas Gleixner
2021-09-28 12:24 ` [patch 5/5] sched: Move mmdrop to RCU " Thomas Gleixner
2021-09-29 12:02 ` Peter Zijlstra
2021-09-29 13:05 ` Thomas Gleixner
2021-10-01 15:05 ` [tip: sched/core] " tip-bot2 for Thomas Gleixner
2021-10-05 14:11 ` tip-bot2 for Thomas Gleixner
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