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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F4EBC433EF for ; Wed, 29 Sep 2021 22:10:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D73CE6142A for ; Wed, 29 Sep 2021 22:10:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347057AbhI2WMA (ORCPT ); Wed, 29 Sep 2021 18:12:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:60356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345332AbhI2WL7 (ORCPT ); Wed, 29 Sep 2021 18:11:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 80E8460FC2; Wed, 29 Sep 2021 22:10:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632953418; bh=18N3NHo//mXzDyvusQFEFTrLFCZXw6uOQdZJYYX/pkA=; h=From:To:Cc:Subject:Date:From; b=Sv8W5WNgdzYwctrr03XHSlLsBTFfjjUVuMGPTJr9GMnL/W2+zchMYBJJUJhFHRV3a GtHlUUFYN8d2a/fv1tLydODTi2Kp/28x6DRtUcRheA54AWtz7Xxav7JkwguMfigPl9 j9GY9wRV31LrYYcbyONXI8c9k/TvzVZ6hy6x+5A4cyC5X4JEF23etMIrr/OPHGxoq/ leypFPYvAVKZxhG9RKm+fqvU3PSNBuX5pIxnr2pJGxW6usC4ewanvQ6saSzxnLHkhV XQzDR/ZX3vVW0ja2AFcM54AJldF2tWsXipM+9YHG8V6Kv5Zb670mk8vN5FrYtcGqTq hmX+K/tqlbZtw== From: Frederic Weisbecker To: "Paul E . McKenney" Cc: LKML , Frederic Weisbecker , Sebastian Andrzej Siewior , Peter Zijlstra , Uladzislau Rezki , Valentin Schneider , Thomas Gleixner , Boqun Feng , Neeraj Upadhyay , Josh Triplett , Joel Fernandes , rcu@vger.kernel.org Subject: [PATCH 00/11] rcu: Make rcu_core() safe in PREEMPT_RT with NOCB + a few other fixes Date: Thu, 30 Sep 2021 00:10:01 +0200 Message-Id: <20210929221012.228270-1-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org PREEMPT_RT has made rcu_core() preemptible, making it unsafe against concurrent NOCB (de-)offloading. Thomas suggested to drop the local_lock() based solution and simply check the offloaded state while context looks safe but that's not enough. Here is a bit of rework. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git rcu/rt HEAD: aac1c58961446c731f2e989bd822ca1fd2659bad Thanks, Frederic --- Frederic Weisbecker (10): rcu/nocb: Make local rcu_nocb_lock_irqsave() safe against concurrent deoffloading rcu/nocb: Prepare state machine for a new step rcu/nocb: Invoke rcu_core() at the start of deoffloading rcu/nocb: Make rcu_core() callbacks acceleration (de-)offloading safe rcu/nocb: Check a stable offloaded state to manipulate qlen_last_fqs_check rcu/nocb: Use appropriate rcu_nocb_lock_irqsave() rcu/nocb: Limit number of softirq callbacks only on softirq rcu: Fix callbacks processing time limit retaining cond_resched() rcu: Apply callbacks processing time limit only on softirq rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread Thomas Gleixner (1): rcu/nocb: Make rcu_core() callbacks acceleration preempt-safe include/linux/rcu_segcblist.h | 51 +++++++++++++++++++------- kernel/rcu/rcu_segcblist.c | 10 ++--- kernel/rcu/rcu_segcblist.h | 7 ++-- kernel/rcu/tree.c | 85 ++++++++++++++++++++++++++++++------------- kernel/rcu/tree.h | 16 +++++--- kernel/rcu/tree_nocb.h | 29 ++++++++++++--- 6 files changed, 136 insertions(+), 62 deletions(-)