From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-kernel@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Nicholas Piggin <npiggin@gmail.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
"Paul E. McKenney" <paulmck@kernel.org>,
Will Deacon <will@kernel.org>,
Alan Stern <stern@rowland.harvard.edu>,
John Stultz <jstultz@google.com>,
Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>,
Frederic Weisbecker <frederic@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Uladzislau Rezki <urezki@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>,
Ingo Molnar <mingo@redhat.com>, Waiman Long <longman@redhat.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>,
maged.michael@gmail.com, Mateusz Guzik <mjguzik@gmail.com>,
Jonas Oberhauser <jonas.oberhauser@huaweicloud.com>,
rcu@vger.kernel.org, linux-mm@kvack.org, lkmm@lists.linux.dev
Subject: [RFC PATCH v3 0/4] sched+mm: Track lazy active mm existence with hazard pointers
Date: Tue, 8 Oct 2024 09:50:30 -0400 [thread overview]
Message-ID: <20241008135034.1982519-1-mathieu.desnoyers@efficios.com> (raw)
[
I'm posting a v3 taking care of feedback from Peter Zijlstra and Paul
E. McKenney in case it can be useful to try hazard pointers with other
use-cases, or for further benchmarking of active mm tracking impact.
]
Hazard pointers appear to be a good fit for replacing refcount based lazy
active mm tracking.
Highlight:
will-it-scale context_switch1_threads
nr threads (-t) speedup
1 -0.2%
2 +0.4%
3 +0.2%
6 +0.6%
12 +0.8%
24 +3%
48 +12%
96 +21%
192 +28%
384 +4%
768 -0.6%
This series applies on top of v6.11.1.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: John Stultz <jstultz@google.com>
Cc: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Zqiang <qiang.zhang1211@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: maged.michael@gmail.com
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Jonas Oberhauser <jonas.oberhauser@huaweicloud.com>
Cc: rcu@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: lkmm@lists.linux.dev
Mathieu Desnoyers (4):
compiler.h: Introduce ptr_eq() to preserve address dependency
Documentation: RCU: Refer to ptr_eq()
hazptr: Implement Hazard Pointers
sched+mm: Use hazard pointers to track lazy active mm existence
Documentation/RCU/rcu_dereference.rst | 38 +++++-
Documentation/mm/active_mm.rst | 9 +-
arch/Kconfig | 32 -----
arch/powerpc/Kconfig | 1 -
arch/powerpc/mm/book3s64/radix_tlb.c | 23 +---
include/linux/compiler.h | 63 ++++++++++
include/linux/hazptr.h | 165 ++++++++++++++++++++++++++
include/linux/mm_types.h | 3 -
include/linux/sched/mm.h | 68 ++++-------
kernel/Makefile | 2 +-
kernel/exit.c | 4 +-
kernel/fork.c | 47 ++------
kernel/hazptr.c | 51 ++++++++
kernel/sched/sched.h | 8 +-
lib/Kconfig.debug | 10 --
15 files changed, 358 insertions(+), 166 deletions(-)
create mode 100644 include/linux/hazptr.h
create mode 100644 kernel/hazptr.c
--
2.39.2
next reply other threads:[~2024-10-08 13:52 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-08 13:50 Mathieu Desnoyers [this message]
2024-10-08 13:50 ` [RFC PATCH v3 1/4] compiler.h: Introduce ptr_eq() to preserve address dependency Mathieu Desnoyers
2024-10-08 13:50 ` [RFC PATCH v3 2/4] Documentation: RCU: Refer to ptr_eq() Mathieu Desnoyers
2024-10-08 13:50 ` [RFC PATCH v3 3/4] hazptr: Implement Hazard Pointers Mathieu Desnoyers
2024-10-08 17:05 ` Mathieu Desnoyers
2024-10-08 13:50 ` [RFC PATCH v3 4/4] sched+mm: Use hazard pointers to track lazy active mm existence Mathieu Desnoyers
2024-10-08 19:51 ` Joel Fernandes
2024-10-14 8:27 ` kernel test robot
2024-10-15 13:33 ` Mathieu Desnoyers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20241008135034.1982519-1-mathieu.desnoyers@efficios.com \
--to=mathieu.desnoyers@efficios.com \
--cc=Neeraj.Upadhyay@amd.com \
--cc=akpm@linux-foundation.org \
--cc=bigeasy@linutronix.de \
--cc=boqun.feng@gmail.com \
--cc=frederic@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=jiangshanlai@gmail.com \
--cc=joel@joelfernandes.org \
--cc=jonas.oberhauser@huaweicloud.com \
--cc=josh@joshtriplett.org \
--cc=jstultz@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lkmm@lists.linux.dev \
--cc=longman@redhat.com \
--cc=maged.michael@gmail.com \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=mjguzik@gmail.com \
--cc=mpe@ellerman.id.au \
--cc=npiggin@gmail.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=qiang.zhang1211@gmail.com \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=stern@rowland.harvard.edu \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=urezki@gmail.com \
--cc=vbabka@suse.cz \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).