From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756174Ab3BRMno (ORCPT ); Mon, 18 Feb 2013 07:43:44 -0500 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:36147 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756020Ab3BRMnk (ORCPT ); Mon, 18 Feb 2013 07:43:40 -0500 From: "Srivatsa S. Bhat" Subject: [PATCH v6 24/46] [SCSI] fcoe: 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 Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, fweisbec@gmail.com, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, walken@google.com, vincent.guittot@linaro.org Date: Mon, 18 Feb 2013 18:11:33 +0530 Message-ID: <20130218124133.26245.87187.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> References: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13021812-5564-0000-0000-000006A6343C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() 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: Robert Love Cc: "James E.J. Bottomley" Cc: devel@open-fcoe.org Cc: linux-scsi@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- drivers/scsi/fcoe/fcoe.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 666b7ac..c971a17 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1475,6 +1475,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, * was originated, otherwise select cpu using rx exchange id * or fcoe_select_cpu(). */ + get_online_cpus_atomic(); if (ntoh24(fh->fh_f_ctl) & FC_FC_EX_CTX) cpu = ntohs(fh->fh_ox_id) & fc_cpu_mask; else { @@ -1484,8 +1485,10 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, cpu = ntohs(fh->fh_rx_id) & fc_cpu_mask; } - if (cpu >= nr_cpu_ids) + if (cpu >= nr_cpu_ids) { + put_online_cpus_atomic(); goto err; + } fps = &per_cpu(fcoe_percpu, cpu); spin_lock(&fps->fcoe_rx_list.lock); @@ -1505,6 +1508,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, spin_lock(&fps->fcoe_rx_list.lock); if (!fps->thread) { spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); goto err; } } @@ -1526,6 +1530,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, if (fps->thread->state == TASK_INTERRUPTIBLE) wake_up_process(fps->thread); spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); return 0; err: From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp01.in.ibm.com (e28smtp01.in.ibm.com [122.248.162.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp01.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 513372C040B for ; Mon, 18 Feb 2013 23:43:38 +1100 (EST) Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Feb 2013 18:10:53 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id ACFC13940053 for ; Mon, 18 Feb 2013 18:13:32 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1IChURu27000872 for ; Mon, 18 Feb 2013 18:13:30 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1IChU3M025818 for ; Mon, 18 Feb 2013 23:43:32 +1100 From: "Srivatsa S. Bhat" Subject: [PATCH v6 24/46] [SCSI] fcoe: 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 Date: Mon, 18 Feb 2013 18:11:33 +0530 Message-ID: <20130218124133.26245.87187.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> References: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-arch@vger.kernel.org, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, netdev@vger.kernel.org, vincent.guittot@linaro.org, walken@google.com, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() 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: Robert Love Cc: "James E.J. Bottomley" Cc: devel@open-fcoe.org Cc: linux-scsi@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- drivers/scsi/fcoe/fcoe.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 666b7ac..c971a17 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1475,6 +1475,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, * was originated, otherwise select cpu using rx exchange id * or fcoe_select_cpu(). */ + get_online_cpus_atomic(); if (ntoh24(fh->fh_f_ctl) & FC_FC_EX_CTX) cpu = ntohs(fh->fh_ox_id) & fc_cpu_mask; else { @@ -1484,8 +1485,10 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, cpu = ntohs(fh->fh_rx_id) & fc_cpu_mask; } - if (cpu >= nr_cpu_ids) + if (cpu >= nr_cpu_ids) { + put_online_cpus_atomic(); goto err; + } fps = &per_cpu(fcoe_percpu, cpu); spin_lock(&fps->fcoe_rx_list.lock); @@ -1505,6 +1508,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, spin_lock(&fps->fcoe_rx_list.lock); if (!fps->thread) { spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); goto err; } } @@ -1526,6 +1530,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, if (fps->thread->state == TASK_INTERRUPTIBLE) wake_up_process(fps->thread); spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); return 0; err: From mboxrd@z Thu Jan 1 00:00:00 1970 From: srivatsa.bhat@linux.vnet.ibm.com (Srivatsa S. Bhat) Date: Mon, 18 Feb 2013 18:11:33 +0530 Subject: [PATCH v6 24/46] [SCSI] fcoe: Use get/put_online_cpus_atomic() to prevent CPU offline In-Reply-To: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> References: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> Message-ID: <20130218124133.26245.87187.stgit@srivatsabhat.in.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() 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: Robert Love Cc: "James E.J. Bottomley" Cc: devel at open-fcoe.org Cc: linux-scsi at vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- drivers/scsi/fcoe/fcoe.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 666b7ac..c971a17 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -1475,6 +1475,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, * was originated, otherwise select cpu using rx exchange id * or fcoe_select_cpu(). */ + get_online_cpus_atomic(); if (ntoh24(fh->fh_f_ctl) & FC_FC_EX_CTX) cpu = ntohs(fh->fh_ox_id) & fc_cpu_mask; else { @@ -1484,8 +1485,10 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, cpu = ntohs(fh->fh_rx_id) & fc_cpu_mask; } - if (cpu >= nr_cpu_ids) + if (cpu >= nr_cpu_ids) { + put_online_cpus_atomic(); goto err; + } fps = &per_cpu(fcoe_percpu, cpu); spin_lock(&fps->fcoe_rx_list.lock); @@ -1505,6 +1508,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, spin_lock(&fps->fcoe_rx_list.lock); if (!fps->thread) { spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); goto err; } } @@ -1526,6 +1530,7 @@ static int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev, if (fps->thread->state == TASK_INTERRUPTIBLE) wake_up_process(fps->thread); spin_unlock(&fps->fcoe_rx_list.lock); + put_online_cpus_atomic(); return 0; err: