From patchwork Thu Feb 21 05:49:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 1045765 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=joelfernandes.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="cD4jri7b"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 444k8R4J5qz9s2R for ; Thu, 21 Feb 2019 16:50:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726988AbfBUFuH (ORCPT ); Thu, 21 Feb 2019 00:50:07 -0500 Received: from mail-qk1-f194.google.com ([209.85.222.194]:33466 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbfBUFuF (ORCPT ); Thu, 21 Feb 2019 00:50:05 -0500 Received: by mail-qk1-f194.google.com with SMTP id x9so3627153qkf.0 for ; Wed, 20 Feb 2019 21:50:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Nv7hlAboBR8L2d9iWBFCyqBxcQDbn2qbimp9HVyPCpU=; b=cD4jri7b+UoIGO3mo90h05zxo//ZEQOkVVfU8eLmaukA3Qx9dexvFlsWoDfh2YynV2 tvzghbBkC2P0wqpE1wwjrvrsarXMxPPY+uqMuUriFWzu7ZCLJqe+t1rVqntH2CIE/6K4 bu2JYMFh1/uA69c7iEUEw3drY6W6UIJloY+as= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=Nv7hlAboBR8L2d9iWBFCyqBxcQDbn2qbimp9HVyPCpU=; b=UVeAXC8FYXGujTZw1yLasdjVCkKtW5fg6lLDY/LQt/bOFpRoZgk0QrK1k/ZvO8Fd6R WI0CcDBdUFst9IMrrTrxpXZwPiHZK3Nr0L4XnrMkn1+doNSTCb+vq8ar+XpyxP/C5d0a C9H71SBBSJftiyqBe8SoFgFswame2pQl7/2xEeBuw5r/Wn3tBb375Wk75JzRVfG6eFic u8z35uOJ7OKAsUm013ZmS7x/nVvFn27mkQIH5lKoadHvNUbcK1++FbfMwGBpYPLtprQl ecWRmaVPZvGKv+RNEldB/f69/1JOrsfiUYCK9m1tr+68eF0tjLl49+wSYnbBGrenEyVF vhTA== X-Gm-Message-State: AHQUAuZoC/EaLl9a6O8pwdwFhIq1h5txdzr3fiZxsZB54DkRPoYyT8lB 2D3xm+qcXZt7WqLHm3xR/Sr0wg== X-Google-Smtp-Source: AHgI3IYD251OD9feSlohnYi9tpXZ3AzdO4nIwcK+7mKpsrnA1wnYeSkmdy3EAfBu5zxbgOgBdew/Ww== X-Received: by 2002:a37:7845:: with SMTP id t66mr27515988qkc.103.1550728203902; Wed, 20 Feb 2019 21:50:03 -0800 (PST) Received: from joelaf.cam.corp.google.com ([2620:0:1004:1100:cca9:fccc:8667:9bdc]) by smtp.gmail.com with ESMTPSA id k185sm11561219qkd.62.2019.02.20.21.50.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Feb 2019 21:50:02 -0800 (PST) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Alexei Starovoitov , Christian Brauner , Daniel Borkmann , David Ahern , "David S. Miller" , Ido Schimmel , Ingo Molnar , intel-wired-lan@lists.osuosl.org (moderated list:INTEL ETHERNET DRIVERS), Jakub Kicinski , Jeff Kirsher , Jesper Dangaard Brouer , John Fastabend , Josh Triplett , keescook@chromium.org, Lai Jiangshan , Martin KaFai Lau , Mathieu Desnoyers , netdev@vger.kernel.org, "Paul E. McKenney" , Peter Zijlstra , rcu@vger.kernel.org, Song Liu , Steven Rostedt , xdp-newbies@vger.kernel.org, Yonghong Song Subject: [PATCH RFC 4/5] sched/topology: Annonate RCU pointers properly Date: Thu, 21 Feb 2019 00:49:41 -0500 Message-Id: <20190221054942.132388-5-joel@joelfernandes.org> X-Mailer: git-send-email 2.21.0.rc0.258.g878e2cd30e-goog In-Reply-To: <20190221054942.132388-1-joel@joelfernandes.org> References: <20190221054942.132388-1-joel@joelfernandes.org> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The scheduler's topology code uses rcu_assign_pointer() to initialize various pointers. Let us annotate the pointers correctly which also help avoid future bugs. This suppresses the new sparse errors caused by an annotation check I added to rcu_assign_pointer(). Also replace rcu_assign_pointer call on rq->sd with WRITE_ONCE. This should be sufficient for the rq->sd initialization. This fixes sparse errors: kernel//sched/topology.c:378:9: sparse: error: incompatible types in comparison expression (different address spaces) kernel//sched/topology.c:387:9: sparse: error: incompatible types in comparison expression (different address spaces) kernel//sched/topology.c:612:9: sparse: error: incompatible types in comparison expression (different address spaces) kernel//sched/topology.c:615:9: sparse: error: incompatible types in comparison expression (different address spaces) kernel//sched/topology.c:618:9: sparse: error: incompatible types in comparison expression (different address spaces) kernel//sched/topology.c:621:9: sparse: error: incompatible types in comparison expression (different address spaces) Signed-off-by: Joel Fernandes (Google) --- kernel/sched/sched.h | 12 ++++++------ kernel/sched/topology.c | 12 ++++++------ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 2ab545d40381..806703afd4b0 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -780,7 +780,7 @@ struct root_domain { * NULL-terminated list of performance domains intersecting with the * CPUs of the rd. Protected by RCU. */ - struct perf_domain *pd; + struct perf_domain __rcu *pd; }; extern struct root_domain def_root_domain; @@ -1305,13 +1305,13 @@ static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) return sd; } -DECLARE_PER_CPU(struct sched_domain *, sd_llc); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); -DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); -DECLARE_PER_CPU(struct sched_domain *, sd_numa); -DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing); -DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); +DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); extern struct static_key_false sched_asym_cpucapacity; struct sched_group_capacity { diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 3f35ba1d8fde..2eab2e16ded5 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -586,13 +586,13 @@ static void destroy_sched_domains(struct sched_domain *sd) * the cpumask of the domain), this allows us to quickly tell if * two CPUs are in the same cache domain, see cpus_share_cache(). */ -DEFINE_PER_CPU(struct sched_domain *, sd_llc); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc); DEFINE_PER_CPU(int, sd_llc_size); DEFINE_PER_CPU(int, sd_llc_id); -DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); -DEFINE_PER_CPU(struct sched_domain *, sd_numa); -DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing); -DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); +DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); static void update_top_cache_domain(int cpu) @@ -668,7 +668,7 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) rq_attach_root(rq, rd); tmp = rq->sd; - rcu_assign_pointer(rq->sd, sd); + WRITE_ONCE(rq->sd, sd); dirty_sched_domain_sysctl(cpu); destroy_sched_domains(tmp);