From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755820Ab3ARWMF (ORCPT ); Fri, 18 Jan 2013 17:12:05 -0500 Received: from mail-pa0-f47.google.com ([209.85.220.47]:45787 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755282Ab3ARWMC (ORCPT ); Fri, 18 Jan 2013 17:12:02 -0500 Date: Fri, 18 Jan 2013 14:11:57 -0800 From: Tejun Heo To: Linus Torvalds Cc: Arjan van de Ven , Ming Lei , Alex Riesen , Alan Stern , Jens Axboe , USB list , Linux Kernel Mailing List , Rusty Russell Subject: [PATCH 4/5] workqueue: implement current_is_async() Message-ID: <20130118221157.GF24579@htj.dyndns.org> References: <20130116164832.GP2668@htj.dyndns.org> <50F6DD4D.3070808@linux.intel.com> <20130116213032.GS2668@htj.dyndns.org> <20130118012503.GH16568@mtj.dyndns.org> <20130118025936.GJ16568@mtj.dyndns.org> <20130118030407.GK16568@mtj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From 84b233adcca3cacd5cfa8013a5feda7a3db4a9af Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 18 Jan 2013 14:05:56 -0800 This function queries whether %current is an async worker executing an async item. This will be used to implement warning on synchronous request_module() from async workers. Signed-off-by: Tejun Heo --- include/linux/async.h | 1 + kernel/async.c | 14 ++++++++++++++ kernel/workqueue_internal.h | 11 +++++++++++ 3 files changed, 26 insertions(+) diff --git a/include/linux/async.h b/include/linux/async.h index 7a24fe9..345169c 100644 --- a/include/linux/async.h +++ b/include/linux/async.h @@ -52,4 +52,5 @@ extern void async_synchronize_full_domain(struct async_domain *domain); extern void async_synchronize_cookie(async_cookie_t cookie); extern void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *domain); +extern bool current_is_async(void); #endif diff --git a/kernel/async.c b/kernel/async.c index 9d31183..d9bf2a9 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -57,6 +57,8 @@ asynchronous and synchronous parts of the kernel. #include #include +#include "workqueue_internal.h" + static async_cookie_t next_cookie = 1; #define MAX_WORK 32768 @@ -337,3 +339,15 @@ void async_synchronize_cookie(async_cookie_t cookie) async_synchronize_cookie_domain(cookie, &async_running); } EXPORT_SYMBOL_GPL(async_synchronize_cookie); + +/** + * current_is_async - is %current an async worker task? + * + * Returns %true if %current is an async worker task. + */ +bool current_is_async(void) +{ + struct worker *worker = current_wq_worker(); + + return worker && worker->current_func == async_run_entry_fn; +} diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index 02549fa..cc35e7e 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -8,6 +8,7 @@ #define _KERNEL_WORKQUEUE_INTERNAL_H #include +#include struct global_cwq; struct worker_pool; @@ -44,6 +45,16 @@ struct worker { struct workqueue_struct *rescue_wq; /* I: the workqueue to rescue */ }; +/** + * current_wq_worker - return struct worker if %current is a workqueue worker + */ +static inline struct worker *current_wq_worker(void) +{ + if (current->flags & PF_WQ_WORKER) + return kthread_data(current); + return NULL; +} + /* * Scheduler hooks for concurrency managed workqueue. Only to be used from * sched.c and workqueue.c. -- 1.8.0.2