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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04D8BC3A59F for ; Tue, 27 Aug 2019 01:34:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDAEB2173E for ; Tue, 27 Aug 2019 01:34:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="e3Ygvu5J" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728560AbfH0BeN (ORCPT ); Mon, 26 Aug 2019 21:34:13 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:40264 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728447AbfH0BeN (ORCPT ); Mon, 26 Aug 2019 21:34:13 -0400 Received: by mail-pl1-f196.google.com with SMTP id h3so10914467pls.7 for ; Mon, 26 Aug 2019 18:34:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=message-id:from:to:cc:subject:date:mime-version :content-transfer-encoding; bh=xxFI6ubLbfvjqXcL3rM1wnq7rt5BMnyUXxlv1J4AS0Q=; b=e3Ygvu5J0zehwvX/hkR4phMoJOKLlyyexZO8KmLKOZtMg3ljaSQUG2Ds58XnVxxL+N GR2YW0Bb2sLP2U8woHfkxj80klllMOuir65UJxAKM9ecZxY/i1opwESlt+nzcZyEhIXV 8RzM7b2RHkxgtzP74x4xTamgRq/AvYaKy70/o= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:from:to:cc:subject:date:mime-version :content-transfer-encoding; bh=xxFI6ubLbfvjqXcL3rM1wnq7rt5BMnyUXxlv1J4AS0Q=; b=AZcSIL+4n7uMf2rftM1WvyZVQxitYypYQbsDNXnXjxsI4G4c/uyU/3+F43TZWldudS QC+6YPOSE6yLvj0ofb96RygaNht8HFVAl4YnbvP7C/kCpfO2DZGM26BoQTPLHOS/F+WT kC+dNqTI/RqNil6xmVcAsOYrCM1sxkhMEBBy6p+4ov9IHHvlDi5fnSXom+Po9uD7nxCQ 4tOfFtAUHj/ZNGU/IlshJiUL2k6FGj4S+xUNdppbPa3qn53lBknH661hsoC/R7/4hEBX mpfEVz7zLLFLTQW6U5pgTuWf4lgxOe6u4xKby+AibYSehjeutrCzI/Ra/C+ii/tOy6lr oeyw== X-Gm-Message-State: APjAAAVcxuMjAWvGC15fFFbYyA7vqsm4qmL1I5HvxaNwrAT5d9IhdVG/ 2C4rRuAadTRzCwnMjejHq7e1/L93kGY= X-Google-Smtp-Source: APXvYqwjzLrAOwdKPlmJhuS5wQw/M9bUwQQM6llz4Ui6ajHAOO1fUqtwJM3NdgDsWk8wh7+ffL4/ig== X-Received: by 2002:a17:902:f01:: with SMTP id 1mr21244217ply.337.1566869652172; Mon, 26 Aug 2019 18:34:12 -0700 (PDT) Received: from joelaf.cam.corp.google.com ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id n185sm11984541pga.16.2019.08.26.18.34.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Aug 2019 18:34:11 -0700 (PDT) Message-ID: <5d648893.1c69fb81.5e60a.fc6c@mx.google.com> X-Google-Original-Message-ID: 156686963125060@cam.corp.google.com From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Frederic Weisbecker , Jonathan Corbet , Josh Triplett , kernel-team@android.com, Lai Jiangshan , linux-doc@vger.kernel.org, Mathieu Desnoyers , Mauro Carvalho Chehab , "Paul E. McKenney" , rcu@vger.kernel.org, Steven Rostedt Subject: [RFC v1 0/2] RCU dyntick nesting counter cleanups Date: Mon, 26 Aug 2019 21:33:52 -0400 X-Mailer: git-send-email 2.23.0.187.g17f5b7556c-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These patches clean up the usage of dynticks nesting counters simplifying the code, while preserving the usecases. It is a much needed simplification, makes the code less confusing, and prevents future bugs such as those that arise from forgetting that the dynticks_nmi_nesting counter is not a simple counter and can be "crowbarred" in common situations. Several nights of rcutorture testing with CONFIG_RCU_EQS_DEBUG on all RCU kernel configurations have survived without any splats. Further testing is in progress, hence marked as RFC! thanks, - Joel Joel Fernandes (Google) (2): rcu/tree: Clean up dynticks counter usage rcu/tree: Remove dynticks_nmi_nesting counter .../Data-Structures/Data-Structures.rst | 31 ++---- Documentation/RCU/stallwarn.txt | 6 +- kernel/rcu/rcu.h | 4 - kernel/rcu/tree.c | 98 +++++++++---------- kernel/rcu/tree.h | 4 +- kernel/rcu/tree_stall.h | 4 +- 6 files changed, 64 insertions(+), 83 deletions(-) -- 2.23.0.187.g17f5b7556c-goog