From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 4 May 2001 12:46:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 4 May 2001 12:46:39 -0400 Received: from jurassic.park.msu.ru ([195.208.223.243]:3332 "EHLO jurassic.park.msu.ru") by vger.kernel.org with ESMTP id ; Fri, 4 May 2001 12:46:33 -0400 Date: Fri, 4 May 2001 20:46:16 +0400 From: Ivan Kokshaysky To: David Howells Cc: linux-kernel@vger.kernel.org Subject: Re: [patch] 2.4.4 alpha semaphores optimization Message-ID: <20010504204616.A579@jurassic.park.msu.ru> In-Reply-To: <20010503194747.A552@jurassic.park.msu.ru> <14842.988968173@warthog.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="DocE+STaALJfprDB" Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <14842.988968173@warthog.cambridge.redhat.com>; from dhowells@redhat.com on Fri, May 04, 2001 at 10:22:53AM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --DocE+STaALJfprDB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, May 04, 2001 at 10:22:53AM +0100, David Howells wrote: > I don't know whether it will (a) compile, or (b) work... I don't have an alpha > to play with. Neither (a) nor (b) ;-) Corrected asm-alpha/rwsem.h attached. Also small fix for lib/rwsem.c -- RWSEM_WAITING_BIAS-RWSEM_ACTIVE_BIAS won't fit in the __s32 if counters are 64-bit. --- linux/lib/rwsem.c.orig Sat Apr 28 00:58:28 2001 +++ linux/lib/rwsem.c Fri May 4 17:38:06 2001 @@ -112,7 +112,7 @@ static inline struct rw_semaphore *__rws */ static inline struct rw_semaphore *rwsem_down_failed_common(struct rw_semaphore *sem, struct rwsem_waiter *waiter, - __s32 adjustment) + signed long adjustment) { struct task_struct *tsk = current; signed long count; Ivan. --DocE+STaALJfprDB Content-Type: text/plain; charset=us-ascii Content-Description: rwsem.h Content-Disposition: attachment; filename="rwsem64.h" #ifndef _ALPHA_RWSEM_H #define _ALPHA_RWSEM_H /* * Written by Ivan Kokshaysky , 2001. * Based on asm-alpha/semaphore.h and asm-i386/rwsem.h */ #ifndef _LINUX_RWSEM_H #error please dont include asm/rwsem.h directly, use linux/rwsem.h instead #endif #ifdef __KERNEL__ #include #include struct rwsem_waiter; extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem); extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem); extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *); /* * the semaphore definition */ struct rw_semaphore { long count; #define RWSEM_UNLOCKED_VALUE 0x0000000000000000L #define RWSEM_ACTIVE_BIAS 0x0000000000000001L #define RWSEM_ACTIVE_MASK 0x00000000ffffffffL #define RWSEM_WAITING_BIAS (-0x0000000100000000L) #define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) spinlock_t wait_lock; struct list_head wait_list; #if RWSEM_DEBUG int debug; #endif }; #if RWSEM_DEBUG #define __RWSEM_DEBUG_INIT , 0 #else #define __RWSEM_DEBUG_INIT /* */ #endif #define __RWSEM_INITIALIZER(name) \ { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \ LIST_HEAD_INIT((name).wait_list) __RWSEM_DEBUG_INIT } #define DECLARE_RWSEM(name) \ struct rw_semaphore name = __RWSEM_INITIALIZER(name) static inline void init_rwsem(struct rw_semaphore *sem) { sem->count = RWSEM_UNLOCKED_VALUE; spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); #if RWSEM_DEBUG sem->debug = 0; #endif } static inline void __down_read(struct rw_semaphore *sem) { long oldcount, temp; __asm__ __volatile__( "1: ldq_l %0,%1\n" " addq %0,%3,%2\n" " stq_c %2,%1\n" " beq %2,2f\n" #ifdef CONFIG_SMP " mb\n" #endif ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); if (oldcount < 0) rwsem_down_read_failed(sem); } static inline void __down_write(struct rw_semaphore *sem) { long granted, temp; __asm__ __volatile__( "1: ldq_l %0,%1\n" " addq %0,%3,%2\n" " stq_c %2,%1\n" " beq %2,2f\n" #ifdef CONFIG_SMP " mb\n" #endif " cmpeq %0,0,%0\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (granted), "=m" (sem->count), "=&r" (temp) :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); if (!granted) rwsem_down_write_failed(sem); } static inline void __up_read(struct rw_semaphore *sem) { long oldcount, temp; __asm__ __volatile__( #ifdef CONFIG_SMP " mb\n" #endif "1: ldq_l %0,%1\n" " subq %0,%3,%2\n" " stq_c %2,%1\n" " beq %2,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); if (oldcount < 0) if ((oldcount & RWSEM_ACTIVE_MASK) == 0) rwsem_wake(sem); } static inline void __up_write(struct rw_semaphore *sem) { long count, cmp; __asm__ __volatile__( #ifdef CONFIG_SMP " mb\n" #endif "1: ldq_l %0,%1\n" " subq %0,%3,%2\n" " stq_c %2,%1\n" " beq %2,2f\n" " cmpeq %0,%3,%2\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (count), "=m" (sem->count), "=&r" (cmp) :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); if (!cmp) if ((int)count - RWSEM_ACTIVE_BIAS == 0) rwsem_wake(sem); } static inline void rwsem_atomic_add(long val, struct rw_semaphore *sem) { 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)); } static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem) { long temp, ret; __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 /* __KERNEL__ */ #endif /* _ALPHA_RWSEM_H */ --DocE+STaALJfprDB--