From patchwork Sat Jan 5 17:48:59 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13836 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id B958923E21 for ; Sat, 5 Jan 2013 17:49:27 +0000 (UTC) Received: from mail-vb0-f46.google.com (mail-vb0-f46.google.com [209.85.212.46]) by fiordland.canonical.com (Postfix) with ESMTP id 62B94A191C4 for ; Sat, 5 Jan 2013 17:49:27 +0000 (UTC) Received: by mail-vb0-f46.google.com with SMTP id b13so17715192vby.33 for ; Sat, 05 Jan 2013 09:49:27 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:x-forwarded-to:x-forwarded-for:delivered-to:x-received :received-spf:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references:x-content-scanned:x-cbid:x-gm-message-state; bh=16eMYd58qHiMv4RPqC/MP+o3/8WxoHYDXR5W9EejEdY=; b=CkjDjtAwtE4dUZ4dK0TbrX5xRwa/3ZAacsHrM06ZQZMBcTTsC9LHUk7pF8+0ROpLN1 t/9XUs2fqRFdAwj6UTvlj0bEE4MhNHXJU0iW3T7rTxmH23P8alwl1bgCciSHdWM6iTaD 20yRqxqOWNj0fg+UhyFwzomzq7Uxjpup6Cb2phvh2/iaSwJ19o6Ydieynn16cwgxp053 RLgj767tI9igoKhnxOSPSQpuxmdONNcIbDYdrzPPwnYyjYEcaB5SlKOzE+wZnx0+zkjr 7YLPqNnrgj3HK1ox1m7ZORm5nBCKlDcigztelDOjStdPSbM5n4o0OfFHTj/omkO6aq6b 1Pug== X-Received: by 10.52.176.6 with SMTP id ce6mr69264841vdc.57.1357408166917; Sat, 05 Jan 2013 09:49:26 -0800 (PST) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.58.145.101 with SMTP id st5csp17440veb; Sat, 5 Jan 2013 09:49:26 -0800 (PST) X-Received: by 10.50.169.106 with SMTP id ad10mr1908491igc.88.1357408163303; Sat, 05 Jan 2013 09:49:23 -0800 (PST) Received: from e37.co.us.ibm.com (e37.co.us.ibm.com. [32.97.110.158]) by mx.google.com with ESMTPS id g6si260940icx.32.2013.01.05.09.49.22 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 05 Jan 2013 09:49:23 -0800 (PST) Received-SPF: pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.110.158 as permitted sender) client-ip=32.97.110.158; Authentication-Results: mx.google.com; spf=pass (google.com: domain of paulmck@linux.vnet.ibm.com designates 32.97.110.158 as permitted sender) smtp.mail=paulmck@linux.vnet.ibm.com Received: from /spool/local by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 5 Jan 2013 10:49:21 -0700 Received: from d03dlp02.boulder.ibm.com (9.17.202.178) by e37.co.us.ibm.com (192.168.1.137) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Sat, 5 Jan 2013 10:49:19 -0700 Received: from d03relay03.boulder.ibm.com (d03relay03.boulder.ibm.com [9.17.195.228]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id A31383E40052; Sat, 5 Jan 2013 10:49:13 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay03.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r05HnHRK224672; Sat, 5 Jan 2013 10:49:17 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r05HnBQK032261; Sat, 5 Jan 2013 10:49:14 -0700 Received: from paulmck-ThinkPad-W500 ([9.80.23.97]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r05HnATq032183; Sat, 5 Jan 2013 10:49:10 -0700 Received: by paulmck-ThinkPad-W500 (Postfix, from userid 1000) id 4465FE51FF; Sat, 5 Jan 2013 09:49:06 -0800 (PST) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, patches@linaro.org, "Paul E. McKenney" , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 09/14] rcu: Rearrange locking in rcu_start_gp() Date: Sat, 5 Jan 2013 09:48:59 -0800 Message-Id: <1357408144-15830-9-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1357408144-15830-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20130105174844.GA14172@linux.vnet.ibm.com> <1357408144-15830-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13010517-7408-0000-0000-00000B9539CA X-Gm-Message-State: ALoCoQnYyrjhaIx4uJxwTIK/ggo9+cObSIoiEblmvjlqHtwpKCqE0tN0HK3hBBvcc1CWkqTuwzXo From: "Paul E. McKenney" If CPUs are to give prior notice of needed grace periods, it will be necessary to invoke rcu_start_gp() without dropping the root rcu_node structure's ->lock. This commit takes a first step in this direction by moving the release of this lock to the end of rcu_start_gp(). Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 4b8d91c..7207435 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1559,16 +1559,14 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } - rsp->gp_flags = RCU_GP_FLAG_INIT; - raw_spin_unlock(&rnp->lock); /* Interrupts remain disabled. */ /* Ensure that CPU is aware of completion of last grace period. */ - rcu_process_gp_end(rsp, rdp); - local_irq_restore(flags); + __rcu_process_gp_end(rsp, rdp->mynode, rdp); /* Wake up rcu_gp_kthread() to start the grace period. */ wake_up(&rsp->gp_wq); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } /*