From patchwork Wed May 10 16:51:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13237077 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 B013CC77B7D for ; Wed, 10 May 2023 16:51:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235867AbjEJQvU (ORCPT ); Wed, 10 May 2023 12:51:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231402AbjEJQvS (ORCPT ); Wed, 10 May 2023 12:51:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81D4C7EEA; Wed, 10 May 2023 09:51:17 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 0BCF4635CD; Wed, 10 May 2023 16:51:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C05FC433D2; Wed, 10 May 2023 16:51:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683737476; bh=e5svw6pITw1IMjZGGc9XWb9jqmKkBvDUvNW+meAVtoM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TgykYrWLZJy54+ab8YkUgf6pZbz64aPmLpK8HryLKssVYHTNxFEXuH7pANZGS6Uua p0FqflRaYpEhcuiFdbfv9YKSG17dQYC9do2cIUwTLm8Zx6elRpOwKQiJnTfddE00gq 76dBrbrL/+Tafe+E0rltfeXSq+p5QJvx2X3t4oAOKHUVpJ3kXGrA02C9GXKuWRJW+p OY1TWBHHN3G9WDRw9rF1mHDd3awh0pWOIOG8pJoFhUMi3RjYQZ8c6dhpu4K4RUvgiG CMrPw1HmSEmWvbiqEAJeoy7ewMzjZOh/0pBH8op2s/9YROkqhAjbVvDUDODM082LiY Q18joeQ/cQ+rA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 194D8CE126E; Wed, 10 May 2023 09:51:16 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH rcu 1/3] doc: Get rcutree module parameters back into alpha order Date: Wed, 10 May 2023 09:51:13 -0700 Message-Id: <20230510165115.2187040-1-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <16136ef4-9437-442b-b7c8-3fb6b2120873@paulmck-laptop> References: <16136ef4-9437-442b-b7c8-3fb6b2120873@paulmck-laptop> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org This commit puts the rcutree module parameters back into proper alphabetical order. Signed-off-by: Paul E. McKenney --- .../admin-guide/kernel-parameters.txt | 120 +++++++++--------- 1 file changed, 60 insertions(+), 60 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9e5bab29685f..8a094e2fc381 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4736,43 +4736,6 @@ the propagation of recent CPU-hotplug changes up the rcu_node combining tree. - rcutree.use_softirq= [KNL] - If set to zero, move all RCU_SOFTIRQ processing to - per-CPU rcuc kthreads. Defaults to a non-zero - value, meaning that RCU_SOFTIRQ is used by default. - Specify rcutree.use_softirq=0 to use rcuc kthreads. - - But note that CONFIG_PREEMPT_RT=y kernels disable - this kernel boot parameter, forcibly setting it - to zero. - - rcutree.rcu_fanout_exact= [KNL] - Disable autobalancing of the rcu_node combining - tree. This is used by rcutorture, and might - possibly be useful for architectures having high - cache-to-cache transfer latencies. - - rcutree.rcu_fanout_leaf= [KNL] - Change the number of CPUs assigned to each - leaf rcu_node structure. Useful for very - large systems, which will choose the value 64, - and for NUMA systems with large remote-access - latencies, which will choose a value aligned - with the appropriate hardware boundaries. - - rcutree.rcu_min_cached_objs= [KNL] - Minimum number of objects which are cached and - maintained per one CPU. Object size is equal - to PAGE_SIZE. The cache allows to reduce the - pressure to page allocator, also it makes the - whole algorithm to behave better in low memory - condition. - - rcutree.rcu_delay_page_cache_fill_msec= [KNL] - Set the page-cache refill delay (in milliseconds) - in response to low-memory conditions. The range - of permitted values is in the range 0:100000. - rcutree.jiffies_till_first_fqs= [KNL] Set delay from grace-period initialization to first attempt to force quiescent states. @@ -4811,21 +4774,6 @@ When RCU_NOCB_CPU is set, also adjust the priority of NOCB callback kthreads. - rcutree.rcu_divisor= [KNL] - Set the shift-right count to use to compute - the callback-invocation batch limit bl from - the number of callbacks queued on this CPU. - The result will be bounded below by the value of - the rcutree.blimit kernel parameter. Every bl - callbacks, the softirq handler will exit in - order to allow the CPU to do other work. - - Please note that this callback-invocation batch - limit applies only to non-offloaded callback - invocation. Offloaded callbacks are instead - invoked in the context of an rcuoc kthread, which - scheduler will preempt as it does any other task. - rcutree.nocb_nobypass_lim_per_jiffy= [KNL] On callback-offloaded (rcu_nocbs) CPUs, RCU reduces the lock contention that would @@ -4839,14 +4787,6 @@ the ->nocb_bypass queue. The definition of "too many" is supplied by this kernel boot parameter. - rcutree.rcu_nocb_gp_stride= [KNL] - Set the number of NOCB callback kthreads in - each group, which defaults to the square root - of the number of CPUs. Larger numbers reduce - the wakeup overhead on the global grace-period - kthread, but increases that same overhead on - each group's NOCB grace-period kthread. - rcutree.qhimark= [KNL] Set threshold of queued RCU callbacks beyond which batch limiting is disabled. @@ -4864,6 +4804,56 @@ on rcutree.qhimark at boot time and to zero to disable more aggressive help enlistment. + rcutree.rcu_delay_page_cache_fill_msec= [KNL] + Set the page-cache refill delay (in milliseconds) + in response to low-memory conditions. The range + of permitted values is in the range 0:100000. + + rcutree.rcu_divisor= [KNL] + Set the shift-right count to use to compute + the callback-invocation batch limit bl from + the number of callbacks queued on this CPU. + The result will be bounded below by the value of + the rcutree.blimit kernel parameter. Every bl + callbacks, the softirq handler will exit in + order to allow the CPU to do other work. + + Please note that this callback-invocation batch + limit applies only to non-offloaded callback + invocation. Offloaded callbacks are instead + invoked in the context of an rcuoc kthread, which + scheduler will preempt as it does any other task. + + rcutree.rcu_fanout_exact= [KNL] + Disable autobalancing of the rcu_node combining + tree. This is used by rcutorture, and might + possibly be useful for architectures having high + cache-to-cache transfer latencies. + + rcutree.rcu_fanout_leaf= [KNL] + Change the number of CPUs assigned to each + leaf rcu_node structure. Useful for very + large systems, which will choose the value 64, + and for NUMA systems with large remote-access + latencies, which will choose a value aligned + with the appropriate hardware boundaries. + + rcutree.rcu_min_cached_objs= [KNL] + Minimum number of objects which are cached and + maintained per one CPU. Object size is equal + to PAGE_SIZE. The cache allows to reduce the + pressure to page allocator, also it makes the + whole algorithm to behave better in low memory + condition. + + rcutree.rcu_nocb_gp_stride= [KNL] + Set the number of NOCB callback kthreads in + each group, which defaults to the square root + of the number of CPUs. Larger numbers reduce + the wakeup overhead on the global grace-period + kthread, but increases that same overhead on + each group's NOCB grace-period kthread. + rcutree.rcu_kick_kthreads= [KNL] Cause the grace-period kthread to get an extra wake_up() if it sleeps three times longer than @@ -4885,6 +4875,16 @@ rcu_node tree with an eye towards determining why a new grace period has not yet started. + rcutree.use_softirq= [KNL] + If set to zero, move all RCU_SOFTIRQ processing to + per-CPU rcuc kthreads. Defaults to a non-zero + value, meaning that RCU_SOFTIRQ is used by default. + Specify rcutree.use_softirq=0 to use rcuc kthreads. + + But note that CONFIG_PREEMPT_RT=y kernels disable + this kernel boot parameter, forcibly setting it + to zero. + rcuscale.gp_async= [KNL] Measure performance of asynchronous grace-period primitives such as call_rcu(). From patchwork Wed May 10 16:51:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13237078 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 31F45C7EE22 for ; Wed, 10 May 2023 16:51:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235924AbjEJQvV (ORCPT ); Wed, 10 May 2023 12:51:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235455AbjEJQvT (ORCPT ); Wed, 10 May 2023 12:51:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA20186B5; Wed, 10 May 2023 09:51:18 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 43278634B9; Wed, 10 May 2023 16:51:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7DEFC433EF; Wed, 10 May 2023 16:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683737477; bh=jremWaBHcocZsb/N0jgll7N8XO9CgE/u9SH2zaTMJSY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E94C47tnPAk06/7Wxbj+rtqW4Sxkw4PtOBMIrIqe5eA9vsDA9sCm6I4Nl10H5/Rht 3ucL9IopS19pcYlCivNvneuealJpqD0/DYxpzyKlShNvEudmuRbidZ80fb1zWfQIdj fjNCpy1hFhwQ0MNrUeVEmA1h7pelKDqOt1Fqg6RyqExqRmb8VJWCBIJZCd6CDi9zyg y9RwiFmzd7ss3aRyfS1LnIv/s4cpeMoKh9LoLIdfIf9TDxxmsMQ6d6kGdWNSsRasxO PPmEsQId5gqkl3moFyTgidTUh2A6gM8DUkaDglkBoMqFfg7RsLanonXT2Xeral1WhH X/VcTD6r0nS1w== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 5E5DCCE126E; Wed, 10 May 2023 09:51:17 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH rcu 2/3] doc: Document the rcutree.rcu_resched_ns module parameter Date: Wed, 10 May 2023 09:51:14 -0700 Message-Id: <20230510165115.2187040-2-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <16136ef4-9437-442b-b7c8-3fb6b2120873@paulmck-laptop> References: <16136ef4-9437-442b-b7c8-3fb6b2120873@paulmck-laptop> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org This commit adds kernel-parameters.txt documentation for the rcutree.rcu_resched_ns module parameter. Signed-off-by: Paul E. McKenney --- Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 8a094e2fc381..c21245c0cce6 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4861,6 +4861,13 @@ This wake_up() will be accompanied by a WARN_ONCE() splat and an ftrace_dump(). + rcutree.rcu_resched_ns= [KNL] + Limit the time spend invoking a batch of RCU + callbacks to the specified number of nanoseconds. + By default, this limit is checked only once + every 32 callbacks in order to limit the pain + inflicted by local_clock() overhead. + rcutree.rcu_unlock_delay= [KNL] In CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels, this specifies an rcu_read_unlock()-time delay From patchwork Wed May 10 16:51:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13237079 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 7730BC7EE25 for ; Wed, 10 May 2023 16:51:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235979AbjEJQvV (ORCPT ); Wed, 10 May 2023 12:51:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35576 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235502AbjEJQvT (ORCPT ); Wed, 10 May 2023 12:51:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C59B986BA; Wed, 10 May 2023 09:51:18 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 5564163F1C; Wed, 10 May 2023 16:51:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B271DC433D2; Wed, 10 May 2023 16:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683737477; bh=KUL1vcxfqxgqiiPaLhc5SP0hmmPIpxfJ9zgCriCqIVE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JDebFwdjgO8FJWuCw/yQ9uxcNy6Yb5/O1wArtwLEdGfPzQFB0rirVM39ODXptVIdy 0WI7HgN1uS5UxA3sEUtc/Y5aaQi02mic7+DP6kpkCnAjd85yS6jbYmbCS8BFg1g2kb K3X2kU1inayBDAgGk4OXQiJa+UfsHjfmKb6+IvjuJisgREPKPy/iqVmfE6KfpoBSJl iSxTo2P1zbs7T6VYuLZAq5MF8dXjUwW93GwuoOo/TLgLukZXDroaGWjERqQNP+cdg9 LSODelVV2uKBMH/ychWoWIleCTAvBvx4Ne2mS7PA3QA9KuNxMnTqAn2VEYveFvss4w sK3rxT2LDTgEQ== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 61A46CE1279; Wed, 10 May 2023 09:51:17 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, Zqiang , "Paul E . McKenney" Subject: [PATCH rcu 3/3] MAINTAINERS: Update qiang1.zhang@intel.com to qiang.zhang1211@gmail.com Date: Wed, 10 May 2023 09:51:15 -0700 Message-Id: <20230510165115.2187040-3-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <16136ef4-9437-442b-b7c8-3fb6b2120873@paulmck-laptop> References: <16136ef4-9437-442b-b7c8-3fb6b2120873@paulmck-laptop> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Zqiang The qiang1.zhang@intel.com email address will no longer be used, so this commit updates to qiang.zhang1211@gmail.com. Signed-off-by: Zqiang Signed-off-by: Paul E. McKenney --- MAINTAINERS | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/MAINTAINERS b/MAINTAINERS index 7e0b87d5aa2e..8af0aabe9bf5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17778,7 +17778,7 @@ M: Boqun Feng R: Steven Rostedt R: Mathieu Desnoyers R: Lai Jiangshan -R: Zqiang +R: Zqiang L: rcu@vger.kernel.org S: Supported W: http://www.rdrop.com/users/paulmck/RCU/