From: Lai Jiangshan <laijs@linux.alibaba.com>
To: linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, "Paul E. McKenney" <paulmck@kernel.org>,
Josh Triplett <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>,
Peter Zijlstra <peterz@infradead.org>,
rcu@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: [PATCH 00/11] rcu: introduce percpu rcu_preempt_depth
Date: Thu, 31 Oct 2019 10:07:55 +0000 [thread overview]
Message-ID: <20191031100806.1326-1-laijs@linux.alibaba.com> (raw)
My mind was occupied with percpu rcu_preempt_depth for
several years since Peter introduced percu preempt_count.
But it was stopped by no good way to avoid the scheduler deadlocks.
Now we have deferred_qs to avoid the deadlocks, it is time to implement it.
During the work, I found two possible? drawbacks (fixed by patch1/2
but patch2 is reverted by patch8 which is a better way).
And my not noticing the order of handling special.b.deferred_qs
ate many debuging energy (patch7).
The percpu rcu_preempt_depth patch is the last patch, patch11.
x86 is the only beneficial arch. But other arch can put
->rcu_read_lock_nesting and ->rcu_read_unlock_special to
thread_info to avoid the function call after we have patch8/9.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: x86@kernel.org
CC: "Paul E. McKenney" <paulmck@kernel.org>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Lai Jiangshan <jiangshanlai@gmail.com>
CC: Joel Fernandes <joel@joelfernandes.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: linux-kernel@vger.kernel.org
CC: rcu@vger.kernel.org
Lai Jiangshan (11):
rcu: avoid leaking exp_deferred_qs into next GP
rcu: fix bug when rcu_exp_handler() in nested interrupt
rcu: clean up rcu_preempt_deferred_qs_irqrestore()
rcu: cleanup rcu_preempt_deferred_qs()
rcu: clean all rcu_read_unlock_special after report qs
rcu: clear t->rcu_read_unlock_special in one go
rcu: set special.b.deferred_qs before wake_up()
rcu: don't use negative ->rcu_read_lock_nesting
rcu: wrap usages of rcu_read_lock_nesting
rcu: clear the special.b.need_qs in rcu_note_context_switch()
x86,rcu: use percpu rcu_preempt_depth
arch/x86/Kconfig | 2 +
arch/x86/include/asm/rcu_preempt_depth.h | 87 +++++++++++++++
arch/x86/kernel/cpu/common.c | 7 ++
arch/x86/kernel/process_32.c | 2 +
arch/x86/kernel/process_64.c | 2 +
include/linux/rcupdate.h | 24 +++++
init/init_task.c | 2 +-
kernel/fork.c | 2 +-
kernel/rcu/Kconfig | 3 +
kernel/rcu/tree_exp.h | 58 ++++------
kernel/rcu/tree_plugin.h | 130 +++++++++++++----------
11 files changed, 220 insertions(+), 99 deletions(-)
create mode 100644 arch/x86/include/asm/rcu_preempt_depth.h
--
2.20.1
next reply other threads:[~2019-10-31 10:09 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-31 10:07 Lai Jiangshan [this message]
2019-10-31 10:07 ` [PATCH 01/11] rcu: avoid leaking exp_deferred_qs into next GP Lai Jiangshan
2019-10-31 13:43 ` Paul E. McKenney
2019-10-31 18:19 ` Lai Jiangshan
2019-10-31 19:00 ` Paul E. McKenney
2019-10-31 10:07 ` [PATCH 02/11] rcu: fix bug when rcu_exp_handler() in nested interrupt Lai Jiangshan
2019-10-31 13:47 ` Paul E. McKenney
2019-10-31 14:20 ` Lai Jiangshan
2019-10-31 14:31 ` Paul E. McKenney
2019-10-31 15:14 ` Lai Jiangshan
2019-10-31 18:52 ` Paul E. McKenney
2019-11-01 0:19 ` Boqun Feng
2019-11-01 2:29 ` Lai Jiangshan
2019-10-31 10:07 ` [PATCH 03/11] rcu: clean up rcu_preempt_deferred_qs_irqrestore() Lai Jiangshan
2019-10-31 13:52 ` Paul E. McKenney
2019-10-31 15:25 ` Lai Jiangshan
2019-10-31 18:57 ` Paul E. McKenney
2019-10-31 19:02 ` Paul E. McKenney
2019-10-31 10:07 ` [PATCH 04/11] rcu: cleanup rcu_preempt_deferred_qs() Lai Jiangshan
2019-10-31 14:10 ` Paul E. McKenney
2019-10-31 14:35 ` Lai Jiangshan
2019-10-31 15:07 ` Paul E. McKenney
2019-10-31 18:33 ` Lai Jiangshan
2019-10-31 22:45 ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 05/11] rcu: clean all rcu_read_unlock_special after report qs Lai Jiangshan
2019-11-01 11:54 ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 06/11] rcu: clear t->rcu_read_unlock_special in one go Lai Jiangshan
2019-11-01 12:10 ` Paul E. McKenney
2019-11-01 16:58 ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 07/11] rcu: set special.b.deferred_qs before wake_up() Lai Jiangshan
2019-10-31 10:08 ` [PATCH 08/11] rcu: don't use negative ->rcu_read_lock_nesting Lai Jiangshan
2019-11-01 12:33 ` Paul E. McKenney
2019-11-16 13:04 ` Lai Jiangshan
2019-11-17 21:53 ` Paul E. McKenney
2019-11-18 1:54 ` Lai Jiangshan
2019-11-18 14:57 ` Paul E. McKenney
2019-10-31 10:08 ` [PATCH 09/11] rcu: wrap usages of rcu_read_lock_nesting Lai Jiangshan
2019-10-31 10:08 ` [PATCH 10/11] rcu: clear the special.b.need_qs in rcu_note_context_switch() Lai Jiangshan
2019-10-31 10:08 ` [PATCH 11/11] x86,rcu: use percpu rcu_preempt_depth Lai Jiangshan
2019-11-01 12:58 ` Paul E. McKenney
2019-11-01 13:13 ` Peter Zijlstra
2019-11-01 14:30 ` Paul E. McKenney
2019-11-01 15:32 ` Lai Jiangshan
2019-11-01 16:21 ` Paul E. McKenney
2019-11-01 15:47 ` Lai Jiangshan
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