Commit efc1d23b authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390: enable ARCH_USE_CMPXCHG_LOCKREF 



Enable ARCH_USE_CMPXCHG_LOCKREF since it shows performance improvements
with Linus' simple stat() test case of up to 50% on a 30 cpu system.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
parent 491f6f8e

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ config S390 
	select ARCH_INLINE_WRITE_UNLOCK_IRQ

	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE

	select ARCH_SAVE_PAGE_KEYS if HIBERNATION

	select ARCH_USE_CMPXCHG_LOCKREF

	select ARCH_WANT_IPC_PARSE_VERSION

	select BUILDTIME_EXTABLE_SORT

	select CLONE_BACKWARDS2

arch/s390/include/asm/spinlock.h

+5 −0
Original line number Diff line number Diff line
@@ -44,6 +44,11 @@ extern void arch_spin_lock_wait_flags(arch_spinlock_t *, unsigned long flags); 
extern int arch_spin_trylock_retry(arch_spinlock_t *);

extern void arch_spin_relax(arch_spinlock_t *lock);



static inline int arch_spin_value_unlocked(arch_spinlock_t lock)

{

	return lock.owner_cpu == 0;

}



static inline void arch_spin_lock(arch_spinlock_t *lp)

{

	int old;