2015-04-01 05:17:37

by Jason Low

Subject: Re: [PATCH 19/25] sched: Use bool function return values of true/false not 1/0

On Mon, Mar 30, 2015 at 4:46 PM, Joe Perches <[email protected]> wrote:

> * try_wait_for_completion - try to decrement a completion without blocking
> * @x: completion structure
> *
> - * Return: 0 if a decrement cannot be done without blocking
> - * 1 if a decrement succeeded.
> + * Return: true if a decrement cannot be done without blocking
> + * false if a decrement succeeded.

Hi Joe,

The boolean logic was reversed in this comment. The function should be
returning false if a decrement cannot be done without blocking, and
true if a decrement succeeded.

2015-04-01 05:46:33

by Joe Perches

Subject: [PATCH V2 19/25] sched: Use bool function return values of true/false not 1/0

Use the normal return values for bool functions

Update the other sets of ret in try_wait_for_completion.

Signed-off-by: Joe Perches <[email protected]>
---

On Tue, 2015-03-31 at 22:17 -0700, Jason Low wrote:
> On Mon, Mar 30, 2015 at 4:46 PM, Joe Perches <[email protected]> wrote:
>
> > * try_wait_for_completion - try to decrement a completion without blocking
> > * @x: completion structure
> > *
> > - * Return: 0 if a decrement cannot be done without blocking
> > - * 1 if a decrement succeeded.
> > + * Return: true if a decrement cannot be done without blocking
> > + * false if a decrement succeeded.
> The boolean logic was reversed in this comment. The function should be
> returning false if a decrement cannot be done without blocking, and
> true if a decrement succeeded.

Hi Jason, right, my typo, thanks for noticing.

kernel/sched/auto_group.h | 2 +-
kernel/sched/completion.c | 16 +++++++++-------
2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/kernel/sched/auto_group.h b/kernel/sched/auto_group.h
index 8bd0471..309b6f2 100644
--- a/kernel/sched/auto_group.h
+++ b/kernel/sched/auto_group.h
@@ -45,7 +45,7 @@ static inline void autogroup_init(struct task_struct *init_task) { }
static inline void autogroup_free(struct task_group *tg) { }
static inline bool task_group_is_autogroup(struct task_group *tg)
{
- return 0;
+ return false;
}

static inline struct task_group *
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 8d0f35d..cbccaa0 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -255,8 +255,8 @@ EXPORT_SYMBOL(wait_for_completion_killable_timeout);
* try_wait_for_completion - try to decrement a completion without blocking
* @x: completion structure
*
- * Return: 0 if a decrement cannot be done without blocking
- * 1 if a decrement succeeded.
+ * Return: false if a decrement cannot be done without blocking
+ * true if a decrement succeeded.
*
* If a completion is being used as a counting completion,
* attempt to decrement the counter without blocking. This
@@ -266,7 +266,7 @@ EXPORT_SYMBOL(wait_for_completion_killable_timeout);
bool try_wait_for_completion(struct completion *x)
{
unsigned long flags;
- int ret = 1;
+ bool ret;

/*
* Since x->done will need to be locked only
@@ -275,13 +275,15 @@ bool try_wait_for_completion(struct completion *x)
* return early in the blocking case.
*/
if (!READ_ONCE(x->done))
- return 0;
+ return false;

spin_lock_irqsave(&x->wait.lock, flags);
- if (!x->done)
- ret = 0;
- else
+ if (!x->done) {
+ ret = false;
+ } else {
x->done--;
+ ret = true;
+ }
spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}