Re: [PATCH] locking/percpu-rwsem: Add DEFINE_PERCPU_RWSEM(), use it to initialize cgroup_threadgroup_rwsem

From: Oleg Nesterov
Date: Wed Apr 24 2019 - 07:00:36 EST


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@xxxxxxxxxx/

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.