From patchwork Wed May 15 08:23:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 10944393 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E3AE2924 for ; Wed, 15 May 2019 08:23:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D10D528A22 for ; Wed, 15 May 2019 08:23:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C0D5228A26; Wed, 15 May 2019 08:23:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E94928A22 for ; Wed, 15 May 2019 08:23:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726657AbfEOIXo (ORCPT ); Wed, 15 May 2019 04:23:44 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:60276 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726260AbfEOIXe (ORCPT ); Wed, 15 May 2019 04:23:34 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4F8C26B023927 for ; Wed, 15 May 2019 04:23:33 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sgdmv4p4b-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 15 May 2019 04:23:32 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 15 May 2019 09:23:27 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4F8NPqY54132820 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 May 2019 08:23:25 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B316A4C044; Wed, 15 May 2019 08:23:25 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9FE444C040; Wed, 15 May 2019 08:23:25 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 15 May 2019 08:23:25 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id 4B21DE0389; Wed, 15 May 2019 10:23:25 +0200 (CEST) From: Christian Borntraeger To: Janosch Frank Cc: KVM , Cornelia Huck , Christian Borntraeger , David Hildenbrand , Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Collin Walling , "Jason J . Herne" Subject: [PATCH] KVM: s390: change default halt poll to 50000 Date: Wed, 15 May 2019 10:23:24 +0200 X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19051508-0016-0000-0000-0000027BE10E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051508-0017-0000-0000-000032D8AFEF Message-Id: <20190515082324.112755-1-borntraeger@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-15_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=669 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905150054 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP older performance measurements indicated that 50000 vs 80000 reduces cpu consumption while still providing the benefit of halt polling. We had this change in the IBM KVM product, but it got lost so it never went upstream. Recent re-measurement indicate that 50k is still better than 80k. Signed-off-by: Christian Borntraeger Acked-by: David Hildenbrand Acked-by: Janosch Frank Acked-by: Cornelia Huck --- arch/s390/include/asm/kvm_host.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index dbe254847e0d..cb63cc7bbf06 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -36,7 +36,7 @@ */ #define KVM_NR_IRQCHIPS 1 #define KVM_IRQCHIP_NUM_PINS 4096 -#define KVM_HALT_POLL_NS_DEFAULT 80000 +#define KVM_HALT_POLL_NS_DEFAULT 50000 /* s390-specific vcpu->requests bit members */ #define KVM_REQ_ENABLE_IBS KVM_ARCH_REQ(0)