From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756462Ab3BRMv4 (ORCPT ); Mon, 18 Feb 2013 07:51:56 -0500 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:58891 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756025Ab3BRMnm (ORCPT ); Mon, 18 Feb 2013 07:43:42 -0500 From: "Srivatsa S. Bhat" Subject: [PATCH v6 23/46] infiniband: ehca: 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 18:11:27 +0530 Message-ID: <20130218124127.26245.52045.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: 13021812-2000-0000-0000-00000AFDDB9B 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: Roland Dreier Signed-off-by: Srivatsa S. Bhat --- drivers/infiniband/hw/ehca/ehca_irq.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/infiniband/hw/ehca/ehca_irq.c b/drivers/infiniband/hw/ehca/ehca_irq.c index 8615d7c..d61936c 100644 --- a/drivers/infiniband/hw/ehca/ehca_irq.c +++ b/drivers/infiniband/hw/ehca/ehca_irq.c @@ -43,6 +43,7 @@ #include #include +#include #include "ehca_classes.h" #include "ehca_irq.h" @@ -653,6 +654,9 @@ void ehca_tasklet_eq(unsigned long data) ehca_process_eq((struct ehca_shca*)data, 1); } +/* + * Must be called under get_online_cpus_atomic() and put_online_cpus_atomic(). + */ static int find_next_online_cpu(struct ehca_comp_pool *pool) { int cpu; @@ -703,6 +707,7 @@ static void queue_comp_task(struct ehca_cq *__cq) int cq_jobs; unsigned long flags; + get_online_cpus_atomic(); cpu_id = find_next_online_cpu(pool); BUG_ON(!cpu_online(cpu_id)); @@ -720,6 +725,7 @@ static void queue_comp_task(struct ehca_cq *__cq) BUG_ON(!cct || !thread); } __queue_comp_task(__cq, cct, thread); + put_online_cpus_atomic(); } static void run_comp_task(struct ehca_cpu_comp_task *cct) @@ -759,6 +765,7 @@ static void comp_task_park(unsigned int cpu) list_splice_init(&cct->cq_list, &list); spin_unlock_irq(&cct->task_lock); + get_online_cpus_atomic(); cpu = find_next_online_cpu(pool); target = per_cpu_ptr(pool->cpu_comp_tasks, cpu); thread = *per_cpu_ptr(pool->cpu_comp_threads, cpu); @@ -768,6 +775,7 @@ static void comp_task_park(unsigned int cpu) __queue_comp_task(cq, target, thread); } spin_unlock_irq(&target->task_lock); + put_online_cpus_atomic(); } static void comp_task_stop(unsigned int cpu, bool online) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp09.in.ibm.com (e28smtp09.in.ibm.com [122.248.162.9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp09.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 7AC552C02FA for ; Mon, 18 Feb 2013 23:43:32 +1100 (EST) Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Feb 2013 18:11:41 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id BF6B0394004D for ; Mon, 18 Feb 2013 18:13:28 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1IChQdc33292454 for ; Mon, 18 Feb 2013 18:13:26 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1IChP6a025596 for ; Mon, 18 Feb 2013 12:43:28 GMT From: "Srivatsa S. Bhat" Subject: [PATCH v6 23/46] infiniband: ehca: 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 18:11:27 +0530 Message-ID: <20130218124127.26245.52045.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: Roland Dreier Signed-off-by: Srivatsa S. Bhat --- drivers/infiniband/hw/ehca/ehca_irq.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/infiniband/hw/ehca/ehca_irq.c b/drivers/infiniband/hw/ehca/ehca_irq.c index 8615d7c..d61936c 100644 --- a/drivers/infiniband/hw/ehca/ehca_irq.c +++ b/drivers/infiniband/hw/ehca/ehca_irq.c @@ -43,6 +43,7 @@ #include #include +#include #include "ehca_classes.h" #include "ehca_irq.h" @@ -653,6 +654,9 @@ void ehca_tasklet_eq(unsigned long data) ehca_process_eq((struct ehca_shca*)data, 1); } +/* + * Must be called under get_online_cpus_atomic() and put_online_cpus_atomic(). + */ static int find_next_online_cpu(struct ehca_comp_pool *pool) { int cpu; @@ -703,6 +707,7 @@ static void queue_comp_task(struct ehca_cq *__cq) int cq_jobs; unsigned long flags; + get_online_cpus_atomic(); cpu_id = find_next_online_cpu(pool); BUG_ON(!cpu_online(cpu_id)); @@ -720,6 +725,7 @@ static void queue_comp_task(struct ehca_cq *__cq) BUG_ON(!cct || !thread); } __queue_comp_task(__cq, cct, thread); + put_online_cpus_atomic(); } static void run_comp_task(struct ehca_cpu_comp_task *cct) @@ -759,6 +765,7 @@ static void comp_task_park(unsigned int cpu) list_splice_init(&cct->cq_list, &list); spin_unlock_irq(&cct->task_lock); + get_online_cpus_atomic(); cpu = find_next_online_cpu(pool); target = per_cpu_ptr(pool->cpu_comp_tasks, cpu); thread = *per_cpu_ptr(pool->cpu_comp_threads, cpu); @@ -768,6 +775,7 @@ static void comp_task_park(unsigned int cpu) __queue_comp_task(cq, target, thread); } spin_unlock_irq(&target->task_lock); + put_online_cpus_atomic(); } static void comp_task_stop(unsigned int cpu, bool online) 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 18:11:27 +0530 Subject: [PATCH v6 23/46] infiniband: ehca: 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: <20130218124127.26245.52045.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: Roland Dreier Signed-off-by: Srivatsa S. Bhat --- drivers/infiniband/hw/ehca/ehca_irq.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/infiniband/hw/ehca/ehca_irq.c b/drivers/infiniband/hw/ehca/ehca_irq.c index 8615d7c..d61936c 100644 --- a/drivers/infiniband/hw/ehca/ehca_irq.c +++ b/drivers/infiniband/hw/ehca/ehca_irq.c @@ -43,6 +43,7 @@ #include #include +#include #include "ehca_classes.h" #include "ehca_irq.h" @@ -653,6 +654,9 @@ void ehca_tasklet_eq(unsigned long data) ehca_process_eq((struct ehca_shca*)data, 1); } +/* + * Must be called under get_online_cpus_atomic() and put_online_cpus_atomic(). + */ static int find_next_online_cpu(struct ehca_comp_pool *pool) { int cpu; @@ -703,6 +707,7 @@ static void queue_comp_task(struct ehca_cq *__cq) int cq_jobs; unsigned long flags; + get_online_cpus_atomic(); cpu_id = find_next_online_cpu(pool); BUG_ON(!cpu_online(cpu_id)); @@ -720,6 +725,7 @@ static void queue_comp_task(struct ehca_cq *__cq) BUG_ON(!cct || !thread); } __queue_comp_task(__cq, cct, thread); + put_online_cpus_atomic(); } static void run_comp_task(struct ehca_cpu_comp_task *cct) @@ -759,6 +765,7 @@ static void comp_task_park(unsigned int cpu) list_splice_init(&cct->cq_list, &list); spin_unlock_irq(&cct->task_lock); + get_online_cpus_atomic(); cpu = find_next_online_cpu(pool); target = per_cpu_ptr(pool->cpu_comp_tasks, cpu); thread = *per_cpu_ptr(pool->cpu_comp_threads, cpu); @@ -768,6 +775,7 @@ static void comp_task_park(unsigned int cpu) __queue_comp_task(cq, target, thread); } spin_unlock_irq(&target->task_lock); + put_online_cpus_atomic(); } static void comp_task_stop(unsigned int cpu, bool online)