From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757981AbZEMAeH (ORCPT ); Tue, 12 May 2009 20:34:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752302AbZEMAdx (ORCPT ); Tue, 12 May 2009 20:33:53 -0400 Received: from rv-out-0506.google.com ([209.85.198.236]:35665 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752599AbZEMAdv (ORCPT ); Tue, 12 May 2009 20:33:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=x0Gpn0EVTgIRyQ87FWk8lro3TkvN+fY35Rfr0JBF8qac2dQEDZjU7jPQ7/mFdq+4js lj0yi/7MYl9ZGYGXOnF/4Twa5SlJhzC8V2LHlAX1zDlp9px0rbiJTv92gsTULt/rNFIY v3xZZgfHjVH71sx8XP1M2c+cZLd5RqxHsNBXw= From: tom.leiming@gmail.com To: arjan@infradead.org Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Ming Lei Subject: [PATCH] kernel:async function call:introduce async_run Date: Wed, 13 May 2009 08:33:49 +0800 Message-Id: <1242174829-4694-1-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 1.6.0.GIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ming Lei In fact, some async function call does not need to check, async_run is right for this kind of function call. Also, async_run is very suitable to used to start a thread in atomic context to do somthing, for now there is no such kind of kernel api, eg. kthread_run can not be started in atomic context. This patch is againt my another patch: kernel/async.c:introduce async_schedule*_atomic please review. Signed-off-by: Ming Lei --- include/linux/async.h | 1 + kernel/async.c | 24 +++++++++++++++++++++++- 2 files changed, 24 insertions(+), 1 deletions(-) diff --git a/include/linux/async.h b/include/linux/async.h index ede9849..5390572 100644 --- a/include/linux/async.h +++ b/include/linux/async.h @@ -16,6 +16,7 @@ typedef u64 async_cookie_t; typedef void (async_func_ptr) (void *data, async_cookie_t cookie); +extern void async_run(async_func_ptr *ptr, void *data); extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data); extern async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data, struct list_head *list); diff --git a/kernel/async.c b/kernel/async.c index 6bf565b..9cc4670 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -60,6 +60,7 @@ asynchronous and synchronous parts of the kernel. static async_cookie_t next_cookie = 1; +#define MAX_COOKIE (~0) #define MAX_THREADS 256 #define MAX_WORK 32768 @@ -207,7 +208,10 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, \ entry->running = running; spin_lock_irqsave(&async_lock, flags); - newcookie = entry->cookie = next_cookie++; + if (atomic == 1) + newcookie = entry->cookie = next_cookie++; + else + newcookie = entry->cookie = MAX_COOKIE; list_add_tail(&entry->list, &async_pending); atomic_inc(&entry_count); spin_unlock_irqrestore(&async_lock, flags); @@ -216,6 +220,24 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, \ } /** + * async_run - schedule a function for asynchronous execution + * @ptr: function to execute asynchronously + * @data: data pointer to pass to the function + * + * Note:we do not allocate a cookie for this kind of aysnchronous + * function to decrease the wait time of async_synchronize_full(). + * In fact, some function does not need to check, async_run is right + * for this kind of function call. Also, async_run is very suitable to + * start a thread to do somthing in atomic context,for now there is no such + * kind of kernel api, eg. kthread_run can not be run in atomic context. + */ +void async_run(async_func_ptr *ptr, void *data) +{ + __async_schedule(ptr, data, &async_running, 2); +} +EXPORT_SYMBOL_GPL(async_run); + +/** * async_schedule - schedule a function for asynchronous execution * @ptr: function to execute asynchronously * @data: data pointer to pass to the function -- 1.6.0.GIT