Messages in this thread Patch in this message | | | From | tom.leiming@gmail ... | Subject | [PATCH] kernel:async function call:introduce async_run_inatomic(v2) | Date | Wed, 13 May 2009 23:51:39 +0800 |
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From: Ming Lei <tom.leiming@gmail.com>
The purpose of this function is to offer a simple way to schedule an asynchronous thread from an atomic context, because there are not any functions which can create and start a kernel thread in atomic contexts now. We use async_running_no_sync as running list to make callers that don't want to synchronize on cookies, so can avoid some side effects for async_synchronize_full().
Part of note for async_run_inatomic and some guideline is from Cornelia Huck.
Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> --- include/linux/async.h | 2 ++ kernel/async.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/include/linux/async.h b/include/linux/async.h index 18ce92b..9ff62af 100644 --- a/include/linux/async.h +++ b/include/linux/async.h @@ -16,6 +16,8 @@ typedef u64 async_cookie_t; typedef void (async_func_ptr) (void *data, async_cookie_t cookie); +extern int async_run_inatomic(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 8663f5b..cb527b3 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -65,6 +65,7 @@ static async_cookie_t next_cookie = 1; static LIST_HEAD(async_pending); static LIST_HEAD(async_running); +static LIST_HEAD(async_running_no_sync); static DEFINE_SPINLOCK(async_lock); static int async_enabled = 0; @@ -222,6 +223,28 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, return newcookie; } + /** + * async_run_inatomic - in atomic contexts schedule a function for + * asynchronous execution + * + * @ptr: function to execute asynchronously + * @data: data pointer to pass to the function + * + * Return zero if success, or else return others if failured + * Note: + * The purpose of this function is to offer a simple way to schedule an + * asynchronous thread from an atomic context, because there are not any + * functions which can create and start a kernel thread in atomic contexts + * now. We use async_running_no_sync as running list to make callers that + * don't want to synchronize on cookies, so can avoid some side effects for + * async_synchronize_full(). + */ +int async_run_inatomic(async_func_ptr *ptr, void *data) +{ + return !__async_schedule(ptr, data, &async_running_no_sync, 1); +} +EXPORT_SYMBOL_GPL(async_run_inatomic); + /** * async_schedule - schedule a function for asynchronous execution * @ptr: function to execute asynchronously -- 1.6.0.GIT
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