Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755343Ab1FXVw0 (ORCPT ); Fri, 24 Jun 2011 17:52:26 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39791 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752785Ab1FXVwZ (ORCPT ); Fri, 24 Jun 2011 17:52:25 -0400 Message-ID: <4E050704.3070409@zytor.com> Date: Fri, 24 Jun 2011 14:52:04 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Peter Zijlstra , Linus Torvalds , Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List , Nick Piggin , Jeremy Fitzhardinge Subject: Re: [PATCH 3/8] x86/ticketlock: Use C for __ticket_spin_unlock References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1390 Lines: 37 On 06/23/2011 06:19 PM, Jeremy Fitzhardinge wrote: > 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 | 33 ++++++++++++++++++--------------- > 1 files changed, 18 insertions(+), 15 deletions(-) > > diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h > index f48a6e3..704b0c3 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"); > + These should be asm volatile, I believe. -hpa -- 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/