From patchwork Tue Jun 25 20:29:24 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: 254373 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 ADBD12C1438 for ; Wed, 26 Jun 2013 06:43:02 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753456Ab3FYUdB (ORCPT ); Tue, 25 Jun 2013 16:33:01 -0400 Received: from e23smtp03.au.ibm.com ([202.81.31.145]:48353 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753317Ab3FYUc7 (ORCPT ); Tue, 25 Jun 2013 16:32:59 -0400 Received: from /spool/local by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 26 Jun 2013 06:23:30 +1000 Received: from d23dlp02.au.ibm.com (202.81.31.213) by e23smtp03.au.ibm.com (202.81.31.209) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 26 Jun 2013 06:23:27 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 9A7DC2BB0051; Wed, 26 Jun 2013 06:32:53 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5PKWill66846882; Wed, 26 Jun 2013 06:32:44 +1000 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r5PKWpKf002672; Wed, 26 Jun 2013 06:32:53 +1000 Received: from srivatsabhat.in.ibm.com ([9.79.199.80]) by d23av01.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r5PKWcPj002585; Wed, 26 Jun 2013 06:32:45 +1000 From: "Srivatsa S. Bhat" Subject: [PATCH v2 21/45] block: 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 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, Jens Axboe , "Srivatsa S. Bhat" Date: Wed, 26 Jun 2013 01:59:24 +0530 Message-ID: <20130625202924.16593.95312.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com> References: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062520-6102-0000-0000-000003C1C45C 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: Jens Axboe Signed-off-by: Srivatsa S. Bhat --- block/blk-softirq.c | 3 +++ 1 file changed, 3 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/block/blk-softirq.c b/block/blk-softirq.c index 467c8de..bbab3d3 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -58,6 +58,7 @@ static void trigger_softirq(void *data) */ static int raise_blk_irq(int cpu, struct request *rq) { + get_online_cpus_atomic(); if (cpu_online(cpu)) { struct call_single_data *data = &rq->csd; @@ -66,8 +67,10 @@ static int raise_blk_irq(int cpu, struct request *rq) data->flags = 0; __smp_call_function_single(cpu, data, 0); + put_online_cpus_atomic(); return 0; } + put_online_cpus_atomic(); return 1; }