From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH v3 41/41] s390: more efficient smp barriers Date: Sun, 10 Jan 2016 16:22:14 +0200 Message-ID: <1452426622-4471-42-git-send-email-mst@redhat.com> References: <1452426622-4471-1-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1452426622-4471-1-git-send-email-mst@redhat.com> Sender: linux-sh-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Arnd Bergmann , linux-arch@vger.kernel.org, Andrew Cooper , Russell King - ARM Linux , virtualization@lists.linux-foundation.org, Stefano Stabellini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Joe Perches , David Miller , linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, adi-buildroot-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, xen-devel@lists.xenproject.org, Martin List-Id: linux-arch.vger.kernel.org As per: lkml.kernel.org/r/20150921112252.3c2937e1@mschwide atomics imply a barrier on s390, so s390 should change smp_mb__before_atomic and smp_mb__after_atomic to barrier() instead of smp_mb() and hence should not use the generic versions. Suggested-by: Peter Zijlstra Suggested-by: Martin Schwidefsky Signed-off-by: Michael S. Tsirkin --- arch/s390/include/asm/barrier.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index 4d26fa4..5c8db3c 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -45,6 +45,9 @@ do { \ ___p1; \ }) +#define __smp_mb__before_atomic() barrier() +#define __smp_mb__after_atomic() barrier() + #include #endif /* __ASM_BARRIER_H */ -- MST From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:57839 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757642AbcAJOWX (ORCPT ); Sun, 10 Jan 2016 09:22:23 -0500 Date: Sun, 10 Jan 2016 16:22:14 +0200 From: "Michael S. Tsirkin" Subject: [PATCH v3 41/41] s390: more efficient smp barriers Message-ID: <1452426622-4471-42-git-send-email-mst@redhat.com> References: <1452426622-4471-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452426622-4471-1-git-send-email-mst@redhat.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Arnd Bergmann , linux-arch@vger.kernel.org, Andrew Cooper , Russell King - ARM Linux , virtualization@lists.linux-foundation.org, Stefano Stabellini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Joe Perches , David Miller , linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, adi-buildroot-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, xen-devel@lists.xenproject.org, Martin Schwidefsky , Heiko Carstens , Ingo Molnar , Davidlohr Bueso , Christian Borntraeger Message-ID: <20160110142214.bHj4WVjqh3EqM5GQFvHefDVhvG7J5NP0yqNz-M7rrPA@z> As per: lkml.kernel.org/r/20150921112252.3c2937e1@mschwide atomics imply a barrier on s390, so s390 should change smp_mb__before_atomic and smp_mb__after_atomic to barrier() instead of smp_mb() and hence should not use the generic versions. Suggested-by: Peter Zijlstra Suggested-by: Martin Schwidefsky Signed-off-by: Michael S. Tsirkin --- arch/s390/include/asm/barrier.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index 4d26fa4..5c8db3c 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -45,6 +45,9 @@ do { \ ___p1; \ }) +#define __smp_mb__before_atomic() barrier() +#define __smp_mb__after_atomic() barrier() + #include #endif /* __ASM_BARRIER_H */ -- MST