Re: [PATCH 15/15] seqlock: drop seqcount_ww_mutex_t

[Christian König <christian.koenig@xxxxxxx>]

Am 07.04.22 um 11:19 schrieb Daniel Vetter:
> On Thu, Apr 07, 2022 at 10:59:46AM +0200, Christian König wrote:
> > Daniel pointed out that this series removes the last user of
> > seqcount_ww_mutex_t, so let's drop this.
> >
> > Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: Will Deacon <will@xxxxxxxxxx>
> > Cc: Waiman Long <longman@xxxxxxxxxx>
> > Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> Yeah I don't think we'll ever need this again, ww_mutex aren't common and
> the ww_mutex+seqlock thing wasn't the brighest idea.
>
> Peter/Ingo, assuming you agree, can you ack this for merging through
> drm-misc, or want to pick this up later on when the last user disappeared
> in Linus' tree?

Mpf, I didn't noticed that removing ww_mutex.h from seqlock.h is causing 
a problem for futex.h.

Just send out a patch to fix this because the build servers are pointing 
out now that drm-misc-next is broken.

Please review ASAP,
Christian.

> Cheers, Daniel
>
> > ---
> >   include/linux/seqlock.h | 8 ++------
> >   1 file changed, 2 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
> > index 37ded6b8fee6..3926e9027947 100644
> > --- a/include/linux/seqlock.h
> > +++ b/include/linux/seqlock.h
> > @@ -17,7 +17,6 @@
> >   #include <linux/kcsan-checks.h>
> >   #include <linux/lockdep.h>
> >   #include <linux/mutex.h>
> > -#include <linux/ww_mutex.h>
> >   #include <linux/preempt.h>
> >   #include <linux/spinlock.h>
> >   
> > @@ -164,7 +163,7 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s)
> >    * static initializer or init function. This enables lockdep to validate
> >    * that the write side critical section is properly serialized.
> >    *
> > - * LOCKNAME:	raw_spinlock, spinlock, rwlock, mutex, or ww_mutex.
> > + * LOCKNAME:	raw_spinlock, spinlock, rwlock or mutex
> >    */
> >   
> >   /*
> > @@ -184,7 +183,6 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s)
> >   #define seqcount_spinlock_init(s, lock)		seqcount_LOCKNAME_init(s, lock, spinlock)
> >   #define seqcount_rwlock_init(s, lock)		seqcount_LOCKNAME_init(s, lock, rwlock)
> >   #define seqcount_mutex_init(s, lock)		seqcount_LOCKNAME_init(s, lock, mutex)
> > -#define seqcount_ww_mutex_init(s, lock)		seqcount_LOCKNAME_init(s, lock, ww_mutex)
> >   
> >   /*
> >    * SEQCOUNT_LOCKNAME()	- Instantiate seqcount_LOCKNAME_t and helpers
> > @@ -277,7 +275,6 @@ SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t,  false,    s->lock,        raw_s
> >   SEQCOUNT_LOCKNAME(spinlock,     spinlock_t,      __SEQ_RT, s->lock,        spin,     spin_lock(s->lock))
> >   SEQCOUNT_LOCKNAME(rwlock,       rwlock_t,        __SEQ_RT, s->lock,        read,     read_lock(s->lock))
> >   SEQCOUNT_LOCKNAME(mutex,        struct mutex,    true,     s->lock,        mutex,    mutex_lock(s->lock))
> > -SEQCOUNT_LOCKNAME(ww_mutex,     struct ww_mutex, true,     &s->lock->base, ww_mutex, ww_mutex_lock(s->lock, NULL))
> >   
> >   /*
> >    * SEQCNT_LOCKNAME_ZERO - static initializer for seqcount_LOCKNAME_t
> > @@ -304,8 +301,7 @@ SEQCOUNT_LOCKNAME(ww_mutex,     struct ww_mutex, true,     &s->lock->base, ww_mu
> >   	__seqprop_case((s),	raw_spinlock,	prop),			\
> >   	__seqprop_case((s),	spinlock,	prop),			\
> >   	__seqprop_case((s),	rwlock,		prop),			\
> > -	__seqprop_case((s),	mutex,		prop),			\
> > -	__seqprop_case((s),	ww_mutex,	prop))
> > +	__seqprop_case((s),	mutex,		prop))
> >   
> >   #define seqprop_ptr(s)			__seqprop(s, ptr)
> >   #define seqprop_sequence(s)		__seqprop(s, sequence)
> > --
> > 2.25.1