From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Borntraeger Subject: [PATCH 3/5] s390: make cpu_relax a barrier again Date: Fri, 21 Oct 2016 13:58:56 +0200 Message-ID: <1477051138-1610-4-git-send-email-borntraeger@de.ibm.com> References: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com> Return-path: In-Reply-To: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra Cc: Nicholas Piggin , linux-kernel@vger.kernel.org, linux-s390 , linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Heiko Carstens , Martin Schwidefsky , Noam Camus , Christian Borntraeger List-Id: linux-arch.vger.kernel.org stop_machine seems to be the only important place for yielding during cpu_relax. This was fixed by using cpu_relax_yield. Therefore, we can now redefine cpu_relax to be a barrier instead. (With the option to do some SMT tuning later on) Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index d05965b..5d262cf 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -236,7 +236,7 @@ static inline unsigned short stap(void) */ void cpu_relax_yield(void); -#define cpu_relax() cpu_relax_yield() +#define cpu_relax() barrier() #define cpu_relax_lowlatency() barrier() #define ECAG_CACHE_ATTRIBUTE 0 -- 2.5.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59135 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755311AbcJUL7U (ORCPT ); Fri, 21 Oct 2016 07:59:20 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u9LBwX7Q085177 for ; Fri, 21 Oct 2016 07:59:19 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 267dd3xb2f-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 21 Oct 2016 07:59:19 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 21 Oct 2016 12:59:18 +0100 From: Christian Borntraeger Subject: [PATCH 3/5] s390: make cpu_relax a barrier again Date: Fri, 21 Oct 2016 13:58:56 +0200 In-Reply-To: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com> References: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com> Message-ID: <1477051138-1610-4-git-send-email-borntraeger@de.ibm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: Nicholas Piggin , linux-kernel@vger.kernel.org, linux-s390 , linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Heiko Carstens , Martin Schwidefsky , Noam Camus , Christian Borntraeger Message-ID: <20161021115856.fJKLRK_13OMXzEawNQaQ7sk3xv0j7th66yLzxw5_m0Q@z> stop_machine seems to be the only important place for yielding during cpu_relax. This was fixed by using cpu_relax_yield. Therefore, we can now redefine cpu_relax to be a barrier instead. (With the option to do some SMT tuning later on) Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index d05965b..5d262cf 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -236,7 +236,7 @@ static inline unsigned short stap(void) */ void cpu_relax_yield(void); -#define cpu_relax() cpu_relax_yield() +#define cpu_relax() barrier() #define cpu_relax_lowlatency() barrier() #define ECAG_CACHE_ATTRIBUTE 0 -- 2.5.5