[PATCH] audit: cleanup prune_tree_thread

[PATCH] audit: cleanup prune_tree_thread

[Jiri Slaby]

We can use kthread_run instead of kthread_create+wake_up_process for
creating the thread.

We do not need to set the task state to TASK_RUNNING after schedule(),
the process is in that state already.

And we do not need to set the state to TASK_INTERRUPTIBLE when not
doing schedule() as we set the state to TASK_RUNNING immediately
afterwards.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: <linux-audit@redhat.com>
---
 kernel/audit_tree.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 5efe9b299a12..25772476fa4a 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -661,10 +661,10 @@ static int tag_mount(struct vfsmount *mnt, void *arg)
 static int prune_tree_thread(void *unused)
 {
 	for (;;) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (list_empty(&prune_list))
+		if (list_empty(&prune_list)) {
+			set_current_state(TASK_INTERRUPTIBLE);
 			schedule();
-		__set_current_state(TASK_RUNNING);
+		}
 
 		mutex_lock(&audit_cmd_mutex);
 		mutex_lock(&audit_filter_mutex);
@@ -693,16 +693,14 @@ static int audit_launch_prune(void)
 {
 	if (prune_thread)
 		return 0;
-	prune_thread = kthread_create(prune_tree_thread, NULL,
+	prune_thread = kthread_run(prune_tree_thread, NULL,
 				"audit_prune_tree");
 	if (IS_ERR(prune_thread)) {
 		pr_err("cannot start thread audit_prune_tree");
 		prune_thread = NULL;
 		return -ENOMEM;
-	} else {
-		wake_up_process(prune_thread);
-		return 0;
 	}
+	return 0;
 }
 
 /* called with audit_filter_mutex */
-- 
2.7.4

Re: [PATCH] audit: cleanup prune_tree_thread

[Paul Moore]

On Thursday, March 31, 2016 10:49:28 AM Jiri Slaby wrote:
> We can use kthread_run instead of kthread_create+wake_up_process for
> creating the thread.
> 
> We do not need to set the task state to TASK_RUNNING after schedule(),
> the process is in that state already.
> 
> And we do not need to set the state to TASK_INTERRUPTIBLE when not
> doing schedule() as we set the state to TASK_RUNNING immediately
> afterwards.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Paul Moore <paul@paul-moore.com>
> Cc: Eric Paris <eparis@redhat.com>
> Cc: <linux-audit@redhat.com>
> ---
>  kernel/audit_tree.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)

Thanks, it looks good to me; merged.

> diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
> index 5efe9b299a12..25772476fa4a 100644
> --- a/kernel/audit_tree.c
> +++ b/kernel/audit_tree.c
> @@ -661,10 +661,10 @@ static int tag_mount(struct vfsmount *mnt, void *arg)
>  static int prune_tree_thread(void *unused)
>  {
>  	for (;;) {
> -		set_current_state(TASK_INTERRUPTIBLE);
> -		if (list_empty(&prune_list))
> +		if (list_empty(&prune_list)) {
> +			set_current_state(TASK_INTERRUPTIBLE);
>  			schedule();
> -		__set_current_state(TASK_RUNNING);
> +		}
> 
>  		mutex_lock(&audit_cmd_mutex);
>  		mutex_lock(&audit_filter_mutex);
> @@ -693,16 +693,14 @@ static int audit_launch_prune(void)
>  {
>  	if (prune_thread)
>  		return 0;
> -	prune_thread = kthread_create(prune_tree_thread, NULL,
> +	prune_thread = kthread_run(prune_tree_thread, NULL,
>  				"audit_prune_tree");
>  	if (IS_ERR(prune_thread)) {
>  		pr_err("cannot start thread audit_prune_tree");
>  		prune_thread = NULL;
>  		return -ENOMEM;
> -	} else {
> -		wake_up_process(prune_thread);
> -		return 0;
>  	}
> +	return 0;
>  }
> 
>  /* called with audit_filter_mutex */

-- 
paul moore
www.paul-moore.com