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 04FB5C2D0ED for ; Sat, 28 Mar 2020 22:17:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDF032074A for ; Sat, 28 Mar 2020 22:17:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="vQejaGRu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727830AbgC1WRM (ORCPT ); Sat, 28 Mar 2020 18:17:12 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:40712 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727070AbgC1WRL (ORCPT ); Sat, 28 Mar 2020 18:17:11 -0400 Received: by mail-qk1-f196.google.com with SMTP id l25so15053319qki.7 for ; Sat, 28 Mar 2020 15:17:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xweZZ/PuKU5Urwn8I1bvMApWVXFcICm6DizzqOoCjjA=; b=vQejaGRuzZaYEdUfpeVw5viLB+lXkY1ZmIG1vaVtWbvquj0mZ+fuxuLtgAfauu6p5O bCnpf2KXc20JxOIUfcd9GP0lywaG3C69TCW3MKyYmix0FlL6nA0Aos3oU6Uxfk/1b92O rHsJirApnyffucCa5R5FDSFtI7ahBD2GhPR2U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xweZZ/PuKU5Urwn8I1bvMApWVXFcICm6DizzqOoCjjA=; b=BH1Nm8REHje8PCTiJoMHl+67tJ2O/MWa3tLzbXfXKK0UZbjJnoUpbVdXu0I77MPf4I zgyrtIHqFaX29asKlulM/EZ3dO9MzfCsUBcJ1g0F4kfZBXrAFB1R5h2Wa/vZSVIOK65m 5hw1PbeJPd05JfLnq1H5YEkWcqBJVdfAWExu58xlj2eL6pglsitDpoT/uCgmR5gjsykq uoHWitzW+o/B+dnE9CkpYqCRj5HKR0dHJH042v+5rPyV3q1VtG3GLhNYO3RlgHKPgaCa MVq/yVIlrqCYHyxUh68FFSeittrskRhat3sWsz17HqghWMgJSF2mjOlx6usxjp/KFVq7 ncXg== X-Gm-Message-State: ANhLgQ1qwHpVBeSZ9lBt+W6AA3dGMcbqhisq9kwAed0yjdRTQOcexymU JTYakTGmfVKhUqi13O0zISgB+YDh/DU= X-Google-Smtp-Source: ADFU+vtchfIp7MmRr0BM5PqLR1+Vw2vhF6c1g65ZAGsKGxM2eB+Hd0x3Kd62RhbRwuOKLHSL8x65+Q== X-Received: by 2002:a05:620a:12bc:: with SMTP id x28mr5493168qki.175.1585433830370; Sat, 28 Mar 2020 15:17:10 -0700 (PDT) Received: from joelaf.cam.corp.google.com ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id k66sm6742950qke.10.2020.03.28.15.17.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 28 Mar 2020 15:17:09 -0700 (PDT) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Andy Lutomirski , Frederic Weisbecker , frextrite@gmail.com, Ingo Molnar , Josh Triplett , kernel-team@android.com, Lai Jiangshan , madhuparnabhowmik04@gmail.com, Mathieu Desnoyers , "Paul E. McKenney" , peterz@infradead.org, Petr Mladek , rcu@vger.kernel.org, rostedt@goodmis.org, tglx@linutronix.de, vpillai@digitalocean.com Subject: [PATCH v2 0/4] RCU dyntick nesting counter cleanups Date: Sat, 28 Mar 2020 18:16:59 -0400 Message-Id: <20200328221703.48171-1-joel@joelfernandes.org> X-Mailer: git-send-email 2.26.0.rc2.310.g2932bb562d-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. rcutorture testing with all TREE RCU configurations succeed with CONFIG_RCU_EQS_DEBUG=y and CONFIG_PROVE_LOCKING=y. v1->v2: - Rebase on v5.6-rc6 Joel Fernandes (Google) (4): Revert b8c17e6664c4 ("rcu: Maintain special bits at bottom of ->dynticks counter") rcu/tree: Add better tracing for dyntick-idle 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 +- include/linux/rcutiny.h | 3 - include/trace/events/rcu.h | 29 +-- kernel/rcu/rcu.h | 4 - kernel/rcu/tree.c | 188 +++++++----------- kernel/rcu/tree.h | 4 +- kernel/rcu/tree_stall.h | 4 +- 8 files changed, 105 insertions(+), 164 deletions(-) -- 2.26.0.rc2.310.g2932bb562d-goog