From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C7BBC4332F for ; Tue, 22 Nov 2022 01:04:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231916AbiKVBEO (ORCPT ); Mon, 21 Nov 2022 20:04:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231825AbiKVBEM (ORCPT ); Mon, 21 Nov 2022 20:04:12 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E9E8D121; Mon, 21 Nov 2022 17:04:11 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CBC0EB818BC; Tue, 22 Nov 2022 01:04:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D5E1C433C1; Tue, 22 Nov 2022 01:04:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669079048; bh=1WsAEwovNFRqPIrTBB1RlDI1n+nRzJzZkVm03kcczKk=; h=Date:From:To:Cc:Subject:Reply-To:From; b=RFBpFGt+aJlV3b9VjxKSIt4mjkPHaRJbVkm/g/gTDZjoVjaTccJHN4czCwAkzzHtt Ja3mBNPB4xKScxE41osTksS/+1qSJ94tmcl0LIwmgwbJ8Aw8Vr4hquSi9j73DYPNen M21i7THoq9GQxpakzCQul/VEuPkBn0quMheCExoiPTsmkjCC/ST6pNxKonG5WUH0KE BssZ4sNe5z4kyn0lFz/zX7sIKG4aYSvtqLWCvpromsvpyAeC/McmZs3Y64xP9h1+HX Hrl1DqvrO4gmcKsJ8hU6FR3Q96EyaAxYjbdEHvweW3pJVyqEmcr8H3hQByKiNVxheG tBJ7nzSCjGcnA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 27AD35C0641; Mon, 21 Nov 2022 17:04:08 -0800 (PST) Date: Mon, 21 Nov 2022 17:04:08 -0800 From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org Subject: [PATCH rcu 0/16 Lazy call_rcu() updates for v6.2 Message-ID: <20221122010408.GA3799268@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! This series provides energy efficiency for nearly-idle systems by making call_rcu() more lazy. Several NOCB changes come along for the ride: 1. Simplify rcu_init_nohz() cpumask handling, courtesy of Zhen Lei. 2. Fix late wakeup when flush of bypass cblist happens, courtesy of "Joel Fernandes (Google)". 3. Fix missing nocb gp wake on rcu_barrier(), courtesy of Frederic Weisbecker. 4. Make call_rcu() lazy to save power, courtesy of "Joel Fernandes (Google)". 5. Refactor code a bit in rcu_nocb_do_flush_bypass(), courtesy of "Joel Fernandes (Google)". 6. Shrinker for lazy rcu, courtesy of Vineeth Pillai. 7. Add laziness and kfree tests, courtesy of "Joel Fernandes (Google)". 8. percpu-refcount: Use call_rcu_flush() for atomic switch, courtesy of "Joel Fernandes (Google)". 9. Use call_rcu_flush() instead of call_rcu, courtesy of "Joel Fernandes (Google)". 10. Use call_rcu_flush() for async reader test, courtesy of "Joel Fernandes (Google)". 11. Use call_rcu_flush() where needed, courtesy of "Joel Fernandes (Google)". 12. scsi/scsi_error: Use call_rcu_flush() instead of call_rcu(), courtesy of Uladzislau Rezki. 13. Make queue_rcu_work() use call_rcu_flush(), courtesy of Uladzislau Rezki. 14. Use call_rcu_flush() instead of call_rcu(), courtesy of "Joel Fernandes (Google)". 15. Use call_rcu_flush() for dst_release(), courtesy of "Joel Fernandes (Google)". 16. devinet: Reduce refcount before grace period, courtesy of Eric Dumazet. Changes since v1: o Add more adjustments to avoid excessive laziness (#15 and #16 above). o Get appropriate Cc lines onto non-RCU patches. https://lore.kernel.org/all/20221019225138.GA2499943@paulmck-ThinkPad-P17-Gen-1/ Thanx, Paul ------------------------------------------------------------------------ b/drivers/scsi/scsi_error.c | 2 b/include/linux/rcupdate.h | 9 + b/kernel/rcu/Kconfig | 8 + b/kernel/rcu/rcu.h | 8 + b/kernel/rcu/rcuscale.c | 67 +++++++++++- b/kernel/rcu/rcutorture.c | 16 +- b/kernel/rcu/sync.c | 2 b/kernel/rcu/tiny.c | 2 b/kernel/rcu/tree.c | 11 + b/kernel/rcu/tree.h | 1 b/kernel/rcu/tree_exp.h | 2 b/kernel/rcu/tree_nocb.h | 34 +----- b/kernel/workqueue.c | 2 b/lib/percpu-refcount.c | 3 b/net/core/dst.c | 2 b/net/ipv4/devinet.c | 19 +-- b/net/rxrpc/conn_object.c | 2 kernel/rcu/rcuscale.c | 2 kernel/rcu/tree.c | 129 +++++++++++++++-------- kernel/rcu/tree.h | 11 + kernel/rcu/tree_nocb.h | 243 ++++++++++++++++++++++++++++++++++++-------- 21 files changed, 434 insertions(+), 141 deletions(-)