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: 255135 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id BFBBE2C0335 for ; Fri, 28 Jun 2013 05:58:54 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754578Ab3F0T6S (ORCPT ); Thu, 27 Jun 2013 15:58:18 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:46818 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754511Ab3F0T6Q (ORCPT ); Thu, 27 Jun 2013 15:58:16 -0400 Received: from /spool/local by e23smtp05.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 28 Jun 2013 05:52:04 +1000 Received: from d23dlp01.au.ibm.com (202.81.31.203) by e23smtp05.au.ibm.com (202.81.31.211) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Fri, 28 Jun 2013 05:52:01 +1000 Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [9.190.235.152]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 44A212CE8044; Fri, 28 Jun 2013 05:58:10 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5RJh88H1835444; Fri, 28 Jun 2013 05:43:09 +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 r5RJw7Zm011148; 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 Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, fweisbec@gmail.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , "Srivatsa S. Bhat" 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: 13062719-1396-0000-0000-0000032F2A80 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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(+) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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);