Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755532AbaA1SVL (ORCPT ); Tue, 28 Jan 2014 13:21:11 -0500 Received: from g4t0014.houston.hp.com ([15.201.24.17]:12955 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755416AbaA1SUH (ORCPT ); Tue, 28 Jan 2014 13:20:07 -0500 From: Waiman Long To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Arnd Bergmann Cc: linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Steven Rostedt , Andrew Morton , Michel Lespinasse , Andi Kleen , Rik van Riel , "Paul E. McKenney" , Linus Torvalds , Raghavendra K T , George Spelvin , Tim Chen , Daniel J Blueman , Alexander Fyodorov , Aswin Chandramouleeswaran , Scott J Norton , Thavatchai Makphaibulchoke , Waiman Long Subject: [PATCH v3 2/2] qspinlock, x86: Enable x86-64 to use queue spinlock Date: Tue, 28 Jan 2014 13:19:11 -0500 Message-Id: <1390933151-1797-3-git-send-email-Waiman.Long@hp.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1390933151-1797-1-git-send-email-Waiman.Long@hp.com> References: <1390933151-1797-1-git-send-email-Waiman.Long@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch makes the necessary changes at the x86 architecture specific layer to enable the use of queue spinlock for x86-64. As x86-32 machines are typically not multi-socket. The benefit of queue spinlock may not be apparent. So queue spinlock is not enabled. Currently, there is some incompatibilities between the para-virtualized spinlock code (which hard-codes the use of ticket spinlock) and the queue spinlock. Therefore, the use of queue spinlock is disabled when the para-virtualized spinlock is enabled. Signed-off-by: Waiman Long --- arch/x86/Kconfig | 1 + arch/x86/include/asm/spinlock.h | 2 ++ arch/x86/include/asm/spinlock_types.h | 4 ++++ 3 files changed, 7 insertions(+), 0 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 03db714..50692b4 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -17,6 +17,7 @@ config X86_64 depends on 64BIT select X86_DEV_DMA_OPS select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_USE_QUEUE_SPINLOCK ### Arch settings config X86 diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index bf156de..cfe51a6 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -43,6 +43,7 @@ extern struct static_key paravirt_ticketlocks_enabled; static __always_inline bool static_key_false(struct static_key *key); +#ifndef CONFIG_QUEUE_SPINLOCK #ifdef CONFIG_PARAVIRT_SPINLOCKS static inline void __ticket_enter_slowpath(arch_spinlock_t *lock) @@ -181,6 +182,7 @@ static __always_inline void arch_spin_lock_flags(arch_spinlock_t *lock, { arch_spin_lock(lock); } +#endif /* !CONFIG_QUEUE_SPINLOCK */ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) { diff --git a/arch/x86/include/asm/spinlock_types.h b/arch/x86/include/asm/spinlock_types.h index 4f1bea1..f501a2a 100644 --- a/arch/x86/include/asm/spinlock_types.h +++ b/arch/x86/include/asm/spinlock_types.h @@ -11,6 +11,9 @@ #define TICKET_SLOWPATH_FLAG ((__ticket_t)0) #endif +#ifdef CONFIG_QUEUE_SPINLOCK +#include +#else #if (CONFIG_NR_CPUS < (256 / __TICKET_LOCK_INC)) typedef u8 __ticket_t; typedef u16 __ticketpair_t; @@ -33,6 +36,7 @@ typedef struct arch_spinlock { } arch_spinlock_t; #define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } } +#endif /* CONFIG_QUEUE_SPINLOCK */ #include -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/