On Mon, May 16, 2016 at 06:12:25PM -0700, Linus Torvalds wrote: > On Mon, May 16, 2016 at 5:37 PM, Jason Low <[email protected]> wrote: > > > > This rest of the series converts the rwsem count variable to an > > atomic_long_t > > since it is used it as an atomic variable. This allows us to also remove > > the rwsem_atomic_{add,update} abstraction and reduce 100+ lines of code. > > I would suggest you merge all the "remove rwsem_atomic_{add,update}" > patches into a single patch. > > I don't see the advantage to splitting those up by architecture, and > it does add noise to the series. > > Other than that it all looks fine to me.
OK, done. --- Subject: locking,rwsem: Remove rwsem_atomic_add() and rwsem_atomic_update() From: Jason Low <[email protected]> Date: Mon, 16 May 2016 17:38:02 -0700 The rwsem-xadd count has been converted to an atomic variable and the rwsem code now directly uses atomic_long_add() and atomic_long_add_return(), so we can remove the arch implementations of rwsem_atomic_add() and rwsem_atomic_update(). Cc: Waiman Long <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Jason Low <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Tim Chen <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Terry Rudd <[email protected]> Cc: Peter Hurley <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Tony Luck <[email protected]> Cc: Matt Turner <[email protected]> Signed-off-by: Jason Low <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> --- arch/alpha/include/asm/rwsem.h | 42 ----------------------------------------- arch/ia64/include/asm/rwsem.h | 7 ------ arch/s390/include/asm/rwsem.h | 37 ------------------------------------ arch/x86/include/asm/rwsem.h | 18 ----------------- include/asm-generic/rwsem.h | 16 --------------- 5 files changed, 120 deletions(-) --- a/arch/alpha/include/asm/rwsem.h +++ b/arch/alpha/include/asm/rwsem.h @@ -191,47 +191,5 @@ static inline void __downgrade_write(str rwsem_downgrade_wake(sem); } -static inline void rwsem_atomic_add(long val, struct rw_semaphore *sem) -{ -#ifndef CONFIG_SMP - sem->count += val; -#else - long temp; - __asm__ __volatile__( - "1: ldq_l %0,%1\n" - " addq %0,%2,%0\n" - " stq_c %0,%1\n" - " beq %0,2f\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (temp), "=m" (sem->count) - :"Ir" (val), "m" (sem->count)); -#endif -} - -static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem) -{ -#ifndef CONFIG_SMP - sem->count += val; - return sem->count; -#else - long ret, temp; - __asm__ __volatile__( - "1: ldq_l %0,%1\n" - " addq %0,%3,%2\n" - " addq %0,%3,%0\n" - " stq_c %2,%1\n" - " beq %2,2f\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (ret), "=m" (sem->count), "=&r" (temp) - :"Ir" (val), "m" (sem->count)); - - return ret; -#endif -} - #endif /* __KERNEL__ */ #endif /* _ALPHA_RWSEM_H */ --- a/arch/ia64/include/asm/rwsem.h +++ b/arch/ia64/include/asm/rwsem.h @@ -151,11 +151,4 @@ __downgrade_write (struct rw_semaphore * rwsem_downgrade_wake(sem); } -/* - * Implement atomic add functionality. These used to be "inline" functions, but GCC v3.1 - * doesn't quite optimize this stuff right and ends up with bad calls to fetchandadd. - */ -#define rwsem_atomic_add(delta, sem) atomic64_add(delta, (atomic64_t *)(&(sem)->count)) -#define rwsem_atomic_update(delta, sem) atomic64_add_return(delta, (atomic64_t *)(&(sem)->count)) - #endif /* _ASM_IA64_RWSEM_H */ --- a/arch/s390/include/asm/rwsem.h +++ b/arch/s390/include/asm/rwsem.h @@ -207,41 +207,4 @@ static inline void __downgrade_write(str rwsem_downgrade_wake(sem); } -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) -{ - signed long old, new; - - asm volatile( - " lg %0,%2\n" - "0: lgr %1,%0\n" - " agr %1,%4\n" - " csg %0,%1,%2\n" - " jl 0b" - : "=&d" (old), "=&d" (new), "=Q" (sem->count) - : "Q" (sem->count), "d" (delta) - : "cc", "memory"); -} - -/* - * implement exchange and add functionality - */ -static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) -{ - signed long old, new; - - asm volatile( - " lg %0,%2\n" - "0: lgr %1,%0\n" - " agr %1,%4\n" - " csg %0,%1,%2\n" - " jl 0b" - : "=&d" (old), "=&d" (new), "=Q" (sem->count) - : "Q" (sem->count), "d" (delta) - : "cc", "memory"); - return new; -} - #endif /* _S390_RWSEM_H */ --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -215,23 +215,5 @@ static inline void __downgrade_write(str : "memory", "cc"); } -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) -{ - asm volatile(LOCK_PREFIX _ASM_ADD "%1,%0" - : "+m" (sem->count) - : "er" (delta)); -} - -/* - * implement exchange and add functionality - */ -static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) -{ - return delta + xadd(&sem->count, delta); -} - #endif /* __KERNEL__ */ #endif /* _ASM_X86_RWSEM_H */ --- a/include/asm-generic/rwsem.h +++ b/include/asm-generic/rwsem.h @@ -107,14 +107,6 @@ static inline void __up_write(struct rw_ } /* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) -{ - atomic_long_add(delta, (atomic_long_t *)&sem->count); -} - -/* * downgrade write lock to read lock */ static inline void __downgrade_write(struct rw_semaphore *sem) @@ -134,13 +126,5 @@ static inline void __downgrade_write(str rwsem_downgrade_wake(sem); } -/* - * implement exchange and add functionality - */ -static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) -{ - return atomic_long_add_return(delta, (atomic_long_t *)&sem->count); -} - #endif /* __KERNEL__ */ #endif /* _ASM_GENERIC_RWSEM_H */
