2019-06-01 22:32:38

by Joel Fernandes

Subject: [RFC 4/6] workqueue: Convert for_each_wq to use built-in list check

list_for_each_entry_rcu now has support to check for RCU reader sections
as well as lock. Just use the support in it, instead of explictly
checking in the caller.

Signed-off-by: Joel Fernandes (Google) <[email protected]>
---
kernel/workqueue.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 9657315405de..91ed7aca16e5 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
* ignored.
*/
#define for_each_pwq(pwq, wq) \
- list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \
- if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \
- else
+ list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \
+ lock_is_held(&(wq->mutex).dep_map))

#ifdef CONFIG_DEBUG_OBJECTS_WORK

--
2.22.0.rc1.311.g5d7573a151-goog

2019-06-05 01:29:44

by Daniel Jordan

Subject: Re: [RFC 4/6] workqueue: Convert for_each_wq to use built-in list check

On Sat, Jun 01, 2019 at 06:27:36PM -0400, Joel Fernandes (Google) wrote:
> list_for_each_entry_rcu now has support to check for RCU reader sections
> as well as lock. Just use the support in it, instead of explictly
> checking in the caller.
>
> Signed-off-by: Joel Fernandes (Google) <[email protected]>
> ---
> kernel/workqueue.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 9657315405de..91ed7aca16e5 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
> * ignored.
> */
> #define for_each_pwq(pwq, wq) \
> - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \
> - if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \
> - else
> + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \
> + lock_is_held(&(wq->mutex).dep_map))
>

I think the definition of assert_rcu_or_wq_mutex can also be deleted.

2019-06-05 13:19:33

by Joel Fernandes

Subject: Re: [RFC 4/6] workqueue: Convert for_each_wq to use built-in list check

On Tue, Jun 4, 2019 at 9:25 PM Daniel Jordan <[email protected]> wrote:
>
> On Sat, Jun 01, 2019 at 06:27:36PM -0400, Joel Fernandes (Google) wrote:
> > list_for_each_entry_rcu now has support to check for RCU reader sections
> > as well as lock. Just use the support in it, instead of explictly
> > checking in the caller.
> >
> > Signed-off-by: Joel Fernandes (Google) <[email protected]>
> > ---
> > kernel/workqueue.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> > index 9657315405de..91ed7aca16e5 100644
> > --- a/kernel/workqueue.c
> > +++ b/kernel/workqueue.c
> > @@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
> > * ignored.
> > */
> > #define for_each_pwq(pwq, wq) \
> > - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \
> > - if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \
> > - else
> > + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \
> > + lock_is_held(&(wq->mutex).dep_map))
> >
>
> I think the definition of assert_rcu_or_wq_mutex can also be deleted.

Sure, will do. Thank you.