From patchwork Wed Nov 23 09:12:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 13053277 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 B0043C47088 for ; Wed, 23 Nov 2022 09:13:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237244AbiKWJN6 (ORCPT ); Wed, 23 Nov 2022 04:13:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237213AbiKWJN5 (ORCPT ); Wed, 23 Nov 2022 04:13:57 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB611106103; Wed, 23 Nov 2022 01:13:55 -0800 (PST) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NHFm21sNqzmW81; Wed, 23 Nov 2022 17:13:22 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 23 Nov 2022 17:13:53 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 23 Nov 2022 17:13:53 +0800 From: Zhen Lei To: "Paul E . McKenney" , Frederic Weisbecker , Neeraj Upadhyay , "Josh Triplett" , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , , CC: Zhen Lei , Stephen Rothwell , Subject: [PATCH] doc: Fix htmldocs build warnings of stallwarn.rst Date: Wed, 23 Nov 2022 17:12:46 +0800 Message-ID: <20221123091246.1890-1-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.37.3.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Documentation/RCU/stallwarn.rst: 401: WARNING: Literal block expected; none found. 428: WARNING: Literal block expected; none found. 445: WARNING: Literal block expected; none found. 459: WARNING: Literal block expected; none found. 468: WARNING: Literal block expected; none found. The literal block need to be indented, so add two spaces to each line. In addition, ':', which is used as a boundary in the literal block, is replaced by '|'. Signed-off-by: Zhen Lei --- Documentation/RCU/stallwarn.rst | 44 ++++++++++++++++----------------- 1 file changed, 22 insertions(+), 22 deletions(-) diff --git a/Documentation/RCU/stallwarn.rst b/Documentation/RCU/stallwarn.rst index c1e92dfef40d501..0f6a58ebf5d7855 100644 --- a/Documentation/RCU/stallwarn.rst +++ b/Documentation/RCU/stallwarn.rst @@ -398,9 +398,9 @@ In kernels built with CONFIG_RCU_CPU_STALL_CPUTIME=y or booted with rcupdate.rcu_cpu_stall_cputime=1, the following additional information is supplied with each RCU CPU stall warning:: -rcu: hardirqs softirqs csw/system -rcu: number: 624 45 0 -rcu: cputime: 69 1 2425 ==> 2500(ms) + rcu: hardirqs softirqs csw/system + rcu: number: 624 45 0 + rcu: cputime: 69 1 2425 ==> 2500(ms) These statistics are collected during the sampling period. The values in row "number:" are the number of hard interrupts, number of soft @@ -412,22 +412,22 @@ in milliseconds. Because user-mode tasks normally do not cause RCU CPU stalls, these tasks are typically kernel tasks, which is why only the system CPU time are considered. -The sampling period is shown as follows: -:<------------first timeout---------->:<-----second timeout----->: -:<--half timeout-->:<--half timeout-->: : -: :<--first period-->: : -: :<-----------second sampling period---------->: -: : : : -: snapshot time point 1st-stall 2nd-stall +The sampling period is shown as follows:: + |<------------first timeout---------->|<-----second timeout----->| + |<--half timeout-->|<--half timeout-->| | + | |<--first period-->| | + | |<-----------second sampling period---------->| + | | | | + | snapshot time point 1st-stall 2nd-stall The following describes four typical scenarios: 1. A CPU looping with interrupts disabled.:: - rcu: hardirqs softirqs csw/system - rcu: number: 0 0 0 - rcu: cputime: 0 0 0 ==> 2500(ms) + rcu: hardirqs softirqs csw/system + rcu: number: 0 0 0 + rcu: cputime: 0 0 0 ==> 2500(ms) Because interrupts have been disabled throughout the measurement interval, there are no interrupts and no context switches. @@ -442,9 +442,9 @@ The following describes four typical scenarios: and CPU time consumed by hard interrupts, along with non-zero CPU time consumed by in-kernel execution.:: - rcu: hardirqs softirqs csw/system - rcu: number: 624 0 0 - rcu: cputime: 49 0 2446 ==> 2500(ms) + rcu: hardirqs softirqs csw/system + rcu: number: 624 0 0 + rcu: cputime: 49 0 2446 ==> 2500(ms) The fact that there are zero softirqs gives a hint that these were disabled, perhaps via local_bh_disable(). It is of course possible @@ -456,18 +456,18 @@ The following describes four typical scenarios: Here, only the number of context switches is zero.:: - rcu: hardirqs softirqs csw/system - rcu: number: 624 45 0 - rcu: cputime: 69 1 2425 ==> 2500(ms) + rcu: hardirqs softirqs csw/system + rcu: number: 624 45 0 + rcu: cputime: 69 1 2425 ==> 2500(ms) This situation hints that the stalled CPU was looping with preemption disabled. 4. No looping, but massive hard and soft interrupts.:: - rcu: hardirqs softirqs csw/system - rcu: number: xx xx 0 - rcu: cputime: xx xx 0 ==> 2500(ms) + rcu: hardirqs softirqs csw/system + rcu: number: xx xx 0 + rcu: cputime: xx xx 0 ==> 2500(ms) Here, the number and CPU time of hard interrupts are all non-zero, but the number of context switches and the in-kernel CPU time consumed