From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758704Ab0KPVIx (ORCPT ); Tue, 16 Nov 2010 16:08:53 -0500 Received: from claw.goop.org ([74.207.240.146]:50402 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758461Ab0KPVIw (ORCPT ); Tue, 16 Nov 2010 16:08:52 -0500 From: Jeremy Fitzhardinge To: Peter Zijlstra Cc: Linux Kernel Mailing List , Nick Piggin , Mathieu Desnoyers , =?UTF-8?q?Am=C3=A9rico=20Wang?= , Eric Dumazet , Jan Beulich , Avi Kivity , Xen-devel , "H. Peter Anvin" , Linux Virtualization , Srivatsa Vaddagiri , Jeremy Fitzhardinge Subject: [PATCH 03/14] x86/ticketlock: Use C for __ticket_spin_unlock Date: Tue, 16 Nov 2010 13:08:34 -0800 Message-Id: <56ed476d4b2ac8cae6146f71a7b17af122cbb30c.1289940821.git.jeremy.fitzhardinge@citrix.com> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeremy Fitzhardinge If we don't need to use a locked inc for unlock, then implement it in C. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/include/asm/spinlock.h | 32 +++++++++++++++++--------------- 1 files changed, 17 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index f48a6e3..0170ba9 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -33,9 +33,21 @@ * On PPro SMP or if we are using OOSTORE, we use a locked operation to unlock * (PPro errata 66, 92) */ -# define UNLOCK_LOCK_PREFIX LOCK_PREFIX +static __always_inline void __ticket_unlock_release(struct arch_spinlock *lock) +{ + if (sizeof(lock->tickets.head) == sizeof(u8)) + asm (LOCK_PREFIX "incb %0" + : "+m" (lock->tickets.head) : : "memory"); + else + asm (LOCK_PREFIX "incw %0" + : "+m" (lock->tickets.head) : : "memory"); + +} #else -# define UNLOCK_LOCK_PREFIX +static __always_inline void __ticket_unlock_release(struct arch_spinlock *lock) +{ + lock->tickets.head++; +} #endif /* @@ -93,14 +105,6 @@ static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) return tmp; } - -static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) -{ - asm volatile(UNLOCK_LOCK_PREFIX "incb %0" - : "+m" (lock->slock) - : - : "memory", "cc"); -} #else static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) { @@ -144,15 +148,13 @@ static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) return tmp; } +#endif static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) { - asm volatile(UNLOCK_LOCK_PREFIX "incw %0" - : "+m" (lock->slock) - : - : "memory", "cc"); + __ticket_unlock_release(lock); + barrier(); /* prevent reordering into locked region */ } -#endif static inline int __ticket_spin_is_locked(arch_spinlock_t *lock) { -- 1.7.2.3 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: [PATCH 03/14] x86/ticketlock: Use C for __ticket_spin_unlock Date: Tue, 16 Nov 2010 13:08:34 -0800 Message-ID: <56ed476d4b2ac8cae6146f71a7b17af122cbb30c.1289940821.git.jeremy.fitzhardinge@citrix.com> References: Return-path: In-Reply-To: In-Reply-To: References: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Peter Zijlstra Cc: Xen-devel , Mathieu Desnoyers , Nick Piggin , Srivatsa Vaddagiri , Linux Kernel Mailing List , Jan Beulich , Eric Dumazet , Jeremy Fitzhardinge , Avi Kivity , "H. Peter Anvin" , =?UTF-8?q?Am=C3=A9rico=20Wang?= , Linux Virtualization List-Id: xen-devel@lists.xenproject.org From: Jeremy Fitzhardinge If we don't need to use a locked inc for unlock, then implement it in C. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/include/asm/spinlock.h | 32 +++++++++++++++++--------------- 1 files changed, 17 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index f48a6e3..0170ba9 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -33,9 +33,21 @@ * On PPro SMP or if we are using OOSTORE, we use a locked operation to unlock * (PPro errata 66, 92) */ -# define UNLOCK_LOCK_PREFIX LOCK_PREFIX +static __always_inline void __ticket_unlock_release(struct arch_spinlock *lock) +{ + if (sizeof(lock->tickets.head) == sizeof(u8)) + asm (LOCK_PREFIX "incb %0" + : "+m" (lock->tickets.head) : : "memory"); + else + asm (LOCK_PREFIX "incw %0" + : "+m" (lock->tickets.head) : : "memory"); + +} #else -# define UNLOCK_LOCK_PREFIX +static __always_inline void __ticket_unlock_release(struct arch_spinlock *lock) +{ + lock->tickets.head++; +} #endif /* @@ -93,14 +105,6 @@ static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) return tmp; } - -static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) -{ - asm volatile(UNLOCK_LOCK_PREFIX "incb %0" - : "+m" (lock->slock) - : - : "memory", "cc"); -} #else static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) { @@ -144,15 +148,13 @@ static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) return tmp; } +#endif static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) { - asm volatile(UNLOCK_LOCK_PREFIX "incw %0" - : "+m" (lock->slock) - : - : "memory", "cc"); + __ticket_unlock_release(lock); + barrier(); /* prevent reordering into locked region */ } -#endif static inline int __ticket_spin_is_locked(arch_spinlock_t *lock) { -- 1.7.2.3