From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755451AbcJUL7W (ORCPT ); Fri, 21 Oct 2016 07:59:22 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59140 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755421AbcJUL7U (ORCPT ); Fri, 21 Oct 2016 07:59:20 -0400 From: Christian Borntraeger 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 Subject: [PATCH 3/5] s390: make cpu_relax a barrier again Date: Fri, 21 Oct 2016 13:58:56 +0200 X-Mailer: git-send-email 2.5.5 In-Reply-To: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com> References: <1477051138-1610-1-git-send-email-borntraeger@de.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16102111-0040-0000-0000-000002F2D929 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16102111-0041-0000-0000-00001D8E037B Message-Id: <1477051138-1610-4-git-send-email-borntraeger@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-10-21_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1610210220 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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