From patchwork Thu Jun 27 19:54:46 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Srivatsa S. Bhat" X-Patchwork-Id: 255176 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 9E6032C0FE7 for ; Fri, 28 Jun 2013 06:08:50 +1000 (EST) Received: from e23smtp04.au.ibm.com (e23smtp04.au.ibm.com [202.81.31.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp04.au.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 4E4492C05A7 for ; Fri, 28 Jun 2013 05:58:11 +1000 (EST) Received: from /spool/local by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 28 Jun 2013 05:43:35 +1000 Received: from d23dlp03.au.ibm.com (202.81.31.214) by e23smtp04.au.ibm.com (202.81.31.210) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Fri, 28 Jun 2013 05:43:34 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 463C53578045 for ; Fri, 28 Jun 2013 05:58:09 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5RJhH0n38404252 for ; Fri, 28 Jun 2013 05:43:17 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r5RJw7Ze011148 for ; Fri, 28 Jun 2013 05:58:09 +1000 Received: from srivatsabhat.in.ibm.com ([9.79.209.72]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r5RJw0hk011083; Fri, 28 Jun 2013 05:58:01 +1000 From: "Srivatsa S. Bhat" Subject: [PATCH v3 14/45] timer: Use get/put_online_cpus_atomic() to prevent CPU offline To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com, David.Laight@aculab.com Date: Fri, 28 Jun 2013 01:24:46 +0530 Message-ID: <20130627195446.29830.13065.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> References: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062719-9264-0000-0000-00000406374A Cc: linux-arch@vger.kernel.org, nikunj@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, wangyun@linux.vnet.ibm.com, "Srivatsa S. Bhat" , netdev@vger.kernel.org, Thomas Gleixner , linuxppc-dev@lists.ozlabs.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Once stop_machine() is gone from the CPU offline path, we won't be able to depend on disabling preemption to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: Thomas Gleixner Signed-off-by: Srivatsa S. Bhat --- kernel/timer.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/timer.c b/kernel/timer.c index 15ffdb3..5db594c 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -729,6 +729,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, timer_stats_timer_set_start_info(timer); BUG_ON(!timer->function); + get_online_cpus_atomic(); base = lock_timer_base(timer, &flags); ret = detach_if_pending(timer, base, false); @@ -768,6 +769,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, out_unlock: spin_unlock_irqrestore(&base->lock, flags); + put_online_cpus_atomic(); return ret; } @@ -926,6 +928,7 @@ void add_timer_on(struct timer_list *timer, int cpu) timer_stats_timer_set_start_info(timer); BUG_ON(timer_pending(timer) || !timer->function); + get_online_cpus_atomic(); spin_lock_irqsave(&base->lock, flags); timer_set_base(timer, base); debug_activate(timer, timer->expires); @@ -940,6 +943,7 @@ void add_timer_on(struct timer_list *timer, int cpu) */ wake_up_nohz_cpu(cpu); spin_unlock_irqrestore(&base->lock, flags); + put_online_cpus_atomic(); } EXPORT_SYMBOL_GPL(add_timer_on);