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* [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem
@ 2019-04-23 16:32 Oleg Nesterov
  2019-04-24 10:31 ` Ingo Molnar
  0 siblings, 1 reply; 5+ messages in thread
From: Oleg Nesterov @ 2019-04-23 16:32 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Paul E. McKenney, Peter Zijlstra, Tejun Heo, linux-kernel

Turn DEFINE_STATIC_PERCPU_RWSEM() into __DEFINE_PERCPU_RWSEM() with the
additional "is_static" argument to introduce DEFINE_PERCPU_RWSEM().

Change cgroup.c to use DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 include/linux/percpu-rwsem.h | 8 ++++++--
 kernel/cgroup/cgroup.c       | 3 +--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
index 6887636..2809b44 100644
--- a/include/linux/percpu-rwsem.h
+++ b/include/linux/percpu-rwsem.h
@@ -17,14 +17,18 @@ struct percpu_rw_semaphore {
 	int			readers_block;
 };
 
-#define DEFINE_STATIC_PERCPU_RWSEM(name)				\
+#define __DEFINE_PERCPU_RWSEM(name, is_static)				\
 static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);		\
-static struct percpu_rw_semaphore name = {				\
+is_static struct percpu_rw_semaphore name = {				\
 	.rss = __RCU_SYNC_INITIALIZER(name.rss),			\
 	.read_count = &__percpu_rwsem_rc_##name,			\
 	.rw_sem = __RWSEM_INITIALIZER(name.rw_sem),			\
 	.writer = __RCUWAIT_INITIALIZER(name.writer),			\
 }
+#define DEFINE_PERCPU_RWSEM(name)		\
+	__DEFINE_PERCPU_RWSEM(name, /* not static */)
+#define DEFINE_STATIC_PERCPU_RWSEM(name)	\
+	__DEFINE_PERCPU_RWSEM(name, static)
 
 extern int __percpu_down_read(struct percpu_rw_semaphore *, int);
 extern void __percpu_up_read(struct percpu_rw_semaphore *);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 3f2b4bd..2510017 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -101,7 +101,7 @@ static DEFINE_SPINLOCK(cgroup_idr_lock);
  */
 static DEFINE_SPINLOCK(cgroup_file_kn_lock);
 
-struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
+DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem);
 
 #define cgroup_assert_mutex_or_rcu_locked()				\
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
@@ -5432,7 +5432,6 @@ int __init cgroup_init(void)
 	int ssid;
 
 	BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16);
-	BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem));
 	BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files));
 	BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files));
 
-- 
2.5.0



^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem
  2019-04-23 16:32 [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem Oleg Nesterov
@ 2019-04-24 10:31 ` Ingo Molnar
  2019-04-24 11:00   ` Oleg Nesterov
  0 siblings, 1 reply; 5+ messages in thread
From: Ingo Molnar @ 2019-04-24 10:31 UTC (permalink / raw)
  To: Oleg Nesterov; +Cc: Paul E. McKenney, Peter Zijlstra, Tejun Heo, linux-kernel


* Oleg Nesterov <oleg@redhat.com> wrote:

> Turn DEFINE_STATIC_PERCPU_RWSEM() into __DEFINE_PERCPU_RWSEM() with the
> additional "is_static" argument to introduce DEFINE_PERCPU_RWSEM().
> 
> Change cgroup.c to use DEFINE_PERCPU_RWSEM(cgroup_threadgroup_rwsem).
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
>  include/linux/percpu-rwsem.h | 8 ++++++--
>  kernel/cgroup/cgroup.c       | 3 +--
>  2 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
> index 6887636..2809b44 100644
> --- a/include/linux/percpu-rwsem.h
> +++ b/include/linux/percpu-rwsem.h
> @@ -17,14 +17,18 @@ struct percpu_rw_semaphore {
>  	int			readers_block;
>  };
>  
> -#define DEFINE_STATIC_PERCPU_RWSEM(name)				\
> +#define __DEFINE_PERCPU_RWSEM(name, is_static)				\
>  static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);		\
> -static struct percpu_rw_semaphore name = {				\
> +is_static struct percpu_rw_semaphore name = {				\
>  	.rss = __RCU_SYNC_INITIALIZER(name.rss),			\
>  	.read_count = &__percpu_rwsem_rc_##name,			\
>  	.rw_sem = __RWSEM_INITIALIZER(name.rw_sem),			\
>  	.writer = __RCUWAIT_INITIALIZER(name.writer),			\
>  }
> +#define DEFINE_PERCPU_RWSEM(name)		\
> +	__DEFINE_PERCPU_RWSEM(name, /* not static */)
> +#define DEFINE_STATIC_PERCPU_RWSEM(name)	\
> +	__DEFINE_PERCPU_RWSEM(name, static)

Which tree is this against? It doesn't apply to tip:master nor latest 
-git.

Thanks,

	Ingo

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem
  2019-04-24 10:31 ` Ingo Molnar
@ 2019-04-24 11:00   ` Oleg Nesterov
  2019-04-24 11:02     ` Ingo Molnar
  0 siblings, 1 reply; 5+ messages in thread
From: Oleg Nesterov @ 2019-04-24 11:00 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Paul E. McKenney, Peter Zijlstra, Tejun Heo, linux-kernel

On 04/24, Ingo Molnar wrote:
>
> > -#define DEFINE_STATIC_PERCPU_RWSEM(name)				\
> > +#define __DEFINE_PERCPU_RWSEM(name, is_static)				\
> >  static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);		\
> > -static struct percpu_rw_semaphore name = {				\
> > +is_static struct percpu_rw_semaphore name = {				\
> >  	.rss = __RCU_SYNC_INITIALIZER(name.rss),			\
> >  	.read_count = &__percpu_rwsem_rc_##name,			\
> >  	.rw_sem = __RWSEM_INITIALIZER(name.rw_sem),			\
> >  	.writer = __RCUWAIT_INITIALIZER(name.writer),			\
> >  }
> > +#define DEFINE_PERCPU_RWSEM(name)		\
> > +	__DEFINE_PERCPU_RWSEM(name, /* not static */)
> > +#define DEFINE_STATIC_PERCPU_RWSEM(name)	\
> > +	__DEFINE_PERCPU_RWSEM(name, static)
>
> Which tree is this against? It doesn't apply to tip:master nor latest

OOPS, sorry Ingo!

I forgot that the change above depends on another cleanup I sent to Paul,

	[PATCH] rcu/sync: kill rcu_sync_type/gp_type
	https://lore.kernel.org/lkml/20190423120724.GA6132@redhat.com/

which does

	-       .rss = __RCU_SYNC_INITIALIZER(name.rss, RCU_SCHED_SYNC),        \
	+       .rss = __RCU_SYNC_INITIALIZER(name.rss),                        \

so lets forget it for now, or may be Paul can take this patch too.

Sorry,

Oleg.


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem
  2019-04-24 11:00   ` Oleg Nesterov
@ 2019-04-24 11:02     ` Ingo Molnar
  2019-04-24 18:34       ` Paul E. McKenney
  0 siblings, 1 reply; 5+ messages in thread
From: Ingo Molnar @ 2019-04-24 11:02 UTC (permalink / raw)
  To: Oleg Nesterov; +Cc: Paul E. McKenney, Peter Zijlstra, Tejun Heo, linux-kernel


* Oleg Nesterov <oleg@redhat.com> wrote:

> On 04/24, Ingo Molnar wrote:
> >
> > > -#define DEFINE_STATIC_PERCPU_RWSEM(name)				\
> > > +#define __DEFINE_PERCPU_RWSEM(name, is_static)				\
> > >  static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);		\
> > > -static struct percpu_rw_semaphore name = {				\
> > > +is_static struct percpu_rw_semaphore name = {				\
> > >  	.rss = __RCU_SYNC_INITIALIZER(name.rss),			\
> > >  	.read_count = &__percpu_rwsem_rc_##name,			\
> > >  	.rw_sem = __RWSEM_INITIALIZER(name.rw_sem),			\
> > >  	.writer = __RCUWAIT_INITIALIZER(name.writer),			\
> > >  }
> > > +#define DEFINE_PERCPU_RWSEM(name)		\
> > > +	__DEFINE_PERCPU_RWSEM(name, /* not static */)
> > > +#define DEFINE_STATIC_PERCPU_RWSEM(name)	\
> > > +	__DEFINE_PERCPU_RWSEM(name, static)
> >
> > Which tree is this against? It doesn't apply to tip:master nor latest
> 
> OOPS, sorry Ingo!
> 
> I forgot that the change above depends on another cleanup I sent to Paul,
> 
> 	[PATCH] rcu/sync: kill rcu_sync_type/gp_type
> 	https://lore.kernel.org/lkml/20190423120724.GA6132@redhat.com/
> 
> which does
> 
> 	-       .rss = __RCU_SYNC_INITIALIZER(name.rss, RCU_SCHED_SYNC),        \
> 	+       .rss = __RCU_SYNC_INITIALIZER(name.rss),                        \
> 
> so lets forget it for now, or may be Paul can take this patch too.

No problem, and both rwsem patches you sent seem fine to me:

Reviewed-by: Ingo Molnar <mingo@kernel.org>
 
Thanks,

	Ingo

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem
  2019-04-24 11:02     ` Ingo Molnar
@ 2019-04-24 18:34       ` Paul E. McKenney
  0 siblings, 0 replies; 5+ messages in thread
From: Paul E. McKenney @ 2019-04-24 18:34 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Oleg Nesterov, Peter Zijlstra, Tejun Heo, linux-kernel

On Wed, Apr 24, 2019 at 01:02:56PM +0200, Ingo Molnar wrote:
> 
> * Oleg Nesterov <oleg@redhat.com> wrote:
> 
> > On 04/24, Ingo Molnar wrote:
> > >
> > > > -#define DEFINE_STATIC_PERCPU_RWSEM(name)				\
> > > > +#define __DEFINE_PERCPU_RWSEM(name, is_static)				\
> > > >  static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);		\
> > > > -static struct percpu_rw_semaphore name = {				\
> > > > +is_static struct percpu_rw_semaphore name = {				\
> > > >  	.rss = __RCU_SYNC_INITIALIZER(name.rss),			\
> > > >  	.read_count = &__percpu_rwsem_rc_##name,			\
> > > >  	.rw_sem = __RWSEM_INITIALIZER(name.rw_sem),			\
> > > >  	.writer = __RCUWAIT_INITIALIZER(name.writer),			\
> > > >  }
> > > > +#define DEFINE_PERCPU_RWSEM(name)		\
> > > > +	__DEFINE_PERCPU_RWSEM(name, /* not static */)
> > > > +#define DEFINE_STATIC_PERCPU_RWSEM(name)	\
> > > > +	__DEFINE_PERCPU_RWSEM(name, static)
> > >
> > > Which tree is this against? It doesn't apply to tip:master nor latest
> > 
> > OOPS, sorry Ingo!
> > 
> > I forgot that the change above depends on another cleanup I sent to Paul,
> > 
> > 	[PATCH] rcu/sync: kill rcu_sync_type/gp_type
> > 	https://lore.kernel.org/lkml/20190423120724.GA6132@redhat.com/
> > 
> > which does
> > 
> > 	-       .rss = __RCU_SYNC_INITIALIZER(name.rss, RCU_SCHED_SYNC),        \
> > 	+       .rss = __RCU_SYNC_INITIALIZER(name.rss),                        \
> > 
> > so lets forget it for now, or may be Paul can take this patch too.
> 
> No problem, and both rwsem patches you sent seem fine to me:
> 
> Reviewed-by: Ingo Molnar <mingo@kernel.org>

I queued patches with Ingo's reviewed-by.  Thank you both!

							Thanx, Paul


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-04-24 18:35 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-04-23 16:32 [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem Oleg Nesterov
2019-04-24 10:31 ` Ingo Molnar
2019-04-24 11:00   ` Oleg Nesterov
2019-04-24 11:02     ` Ingo Molnar
2019-04-24 18:34       ` Paul E. McKenney

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