From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C894C10F13 for ; Tue, 16 Apr 2019 18:02:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CA7A206B6 for ; Tue, 16 Apr 2019 18:02:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730299AbfDPSCs (ORCPT ); Tue, 16 Apr 2019 14:02:48 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:40970 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730244AbfDPSCs (ORCPT ); Tue, 16 Apr 2019 14:02:48 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3GHuFec111082 for ; Tue, 16 Apr 2019 14:02:46 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2rwhc271fe-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 16 Apr 2019 14:02:46 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 16 Apr 2019 19:02:44 +0100 Received: from b06cxnps4074.portsmouth.uk.ibm.com (9.149.109.196) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 16 Apr 2019 19:02:41 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3GI2ej746399592 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Apr 2019 18:02:40 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 714BE11C064; Tue, 16 Apr 2019 18:02:40 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0A67A11C04C; Tue, 16 Apr 2019 18:02:40 +0000 (GMT) Received: from oc7455500831.ibm.com (unknown [9.145.53.104]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 16 Apr 2019 18:02:39 +0000 (GMT) Subject: Re: [PATCH v2 2/2] KVM: s390: provide kvm_arch_no_poll function To: Janosch Frank Cc: KVM , Cornelia Huck , David Hildenbrand , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= References: <20190416180158.112309-1-borntraeger@de.ibm.com> <20190416180158.112309-3-borntraeger@de.ibm.com> From: Christian Borntraeger Openpgp: preference=signencrypt Autocrypt: addr=borntraeger@de.ibm.com; prefer-encrypt=mutual; keydata= mQINBE6cPPgBEAC2VpALY0UJjGmgAmavkL/iAdqul2/F9ONz42K6NrwmT+SI9CylKHIX+fdf J34pLNJDmDVEdeb+brtpwC9JEZOLVE0nb+SR83CsAINJYKG3V1b3Kfs0hydseYKsBYqJTN2j CmUXDYq9J7uOyQQ7TNVoQejmpp5ifR4EzwIFfmYDekxRVZDJygD0wL/EzUr8Je3/j548NLyL 4Uhv6CIPf3TY3/aLVKXdxz/ntbLgMcfZsDoHgDk3lY3r1iwbWwEM2+eYRdSZaR4VD+JRD7p8 0FBadNwWnBce1fmQp3EklodGi5y7TNZ/CKdJ+jRPAAnw7SINhSd7PhJMruDAJaUlbYaIm23A +82g+IGe4z9tRGQ9TAflezVMhT5J3ccu6cpIjjvwDlbxucSmtVi5VtPAMTLmfjYp7VY2Tgr+ T92v7+V96jAfE3Zy2nq52e8RDdUo/F6faxcumdl+aLhhKLXgrozpoe2nL0Nyc2uqFjkjwXXI OBQiaqGeWtxeKJP+O8MIpjyGuHUGzvjNx5S/592TQO3phpT5IFWfMgbu4OreZ9yekDhf7Cvn /fkYsiLDz9W6Clihd/xlpm79+jlhm4E3xBPiQOPCZowmHjx57mXVAypOP2Eu+i2nyQrkapaY IdisDQfWPdNeHNOiPnPS3+GhVlPcqSJAIWnuO7Ofw1ZVOyg/jwARAQABtDRDaHJpc3RpYW4g Qm9ybnRyYWVnZXIgKElCTSkgPGJvcm50cmFlZ2VyQGRlLmlibS5jb20+iQI4BBMBAgAiBQJO nDz4AhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRARe7yAtaYcfOYVD/9sqc6ZdYKD bmDIvc2/1LL0g7OgiA8pHJlYN2WHvIhUoZUIqy8Sw2EFny/nlpPVWfG290JizNS2LZ0mCeGZ 80yt0EpQNR8tLVzLSSr0GgoY0lwsKhAnx3p3AOrA8WXsPL6prLAu3yJI5D0ym4MJ6KlYVIjU ppi4NLWz7ncA2nDwiIqk8PBGxsjdc/W767zOOv7117rwhaGHgrJ2tLxoGWj0uoH3ZVhITP1z gqHXYaehPEELDV36WrSKidTarfThCWW0T3y4bH/mjvqi4ji9emp1/pOWs5/fmd4HpKW+44tD Yt4rSJRSa8lsXnZaEPaeY3nkbWPcy3vX6qafIey5d8dc8Uyaan39WslnJFNEx8cCqJrC77kI vcnl65HaW3y48DezrMDH34t3FsNrSVv5fRQ0mbEed8hbn4jguFAjPt4az1xawSp0YvhzwATJ YmZWRMa3LPx/fAxoolq9cNa0UB3D3jmikWktm+Jnp6aPeQ2Db3C0cDyxcOQY/GASYHY3KNra z8iwS7vULyq1lVhOXg1EeSm+lXQ1Ciz3ub3AhzE4c0ASqRrIHloVHBmh4favY4DEFN19Xw1p 76vBu6QjlsJGjvROW3GRKpLGogQTLslbjCdIYyp3AJq2KkoKxqdeQYm0LZXjtAwtRDbDo71C FxS7i/qfvWJv8ie7bE9A6Wsjn7kCDQROnDz4ARAAmPI1e8xB0k23TsEg8O1sBCTXkV8HSEq7 JlWz7SWyM8oFkJqYAB7E1GTXV5UZcr9iurCMKGSTrSu3ermLja4+k0w71pLxws859V+3z1jr nhB3dGzVZEUhCr3EuN0t8eHSLSMyrlPL5qJ11JelnuhToT6535cLOzeTlECc51bp5Xf6/XSx SMQaIU1nDM31R13o98oRPQnvSqOeljc25aflKnVkSfqWSrZmb4b0bcWUFFUKVPfQ5Z6JEcJg Hp7qPXHW7+tJTgmI1iM/BIkDwQ8qe3Wz8R6rfupde+T70NiId1M9w5rdo0JJsjKAPePKOSDo RX1kseJsTZH88wyJ30WuqEqH9zBxif0WtPQUTjz/YgFbmZ8OkB1i+lrBCVHPdcmvathknAxS bXL7j37VmYNyVoXez11zPYm+7LA2rvzP9WxR8bPhJvHLhKGk2kZESiNFzP/E4r4Wo24GT4eh YrDo7GBHN82V4O9JxWZtjpxBBl8bH9PvGWBmOXky7/bP6h96jFu9ZYzVgIkBP3UYW+Pb1a+b w4A83/5ImPwtBrN324bNUxPPqUWNW0ftiR5b81ms/rOcDC/k/VoN1B+IHkXrcBf742VOLID4 YP+CB9GXrwuF5KyQ5zEPCAjlOqZoq1fX/xGSsumfM7d6/OR8lvUPmqHfAzW3s9n4lZOW5Jfx bbkAEQEAAYkCHwQYAQIACQUCTpw8+AIbDAAKCRARe7yAtaYcfPzbD/9WNGVf60oXezNzSVCL hfS36l/zy4iy9H9rUZFmmmlBufWOATjiGAXnn0rr/Jh6Zy9NHuvpe3tyNYZLjB9pHT6mRZX7 Z1vDxeLgMjTv983TQ2hUSlhRSc6e6kGDJyG1WnGQaqymUllCmeC/p9q5m3IRxQrd0skfdN1V AMttRwvipmnMduy5SdNayY2YbhWLQ2wS3XHJ39a7D7SQz+gUQfXgE3pf3FlwbwZhRtVR3z5u aKjxqjybS3Ojimx4NkWjidwOaUVZTqEecBV+QCzi2oDr9+XtEs0m5YGI4v+Y/kHocNBP0myd pF3OoXvcWdTb5atk+OKcc8t4TviKy1WCNujC+yBSq3OM8gbmk6NwCwqhHQzXCibMlVF9hq5a FiJb8p4QKSVyLhM8EM3HtiFqFJSV7F+h+2W0kDyzBGyE0D8z3T+L3MOj3JJJkfCwbEbTpk4f n8zMboekuNruDw1OADRMPlhoWb+g6exBWx/YN4AY9LbE2KuaScONqph5/HvJDsUldcRN3a5V RGIN40QWFVlZvkKIEkzlzqpAyGaRLhXJPv/6tpoQaCQQoSAc5Z9kM/wEd9e2zMeojcWjUXgg oWj8A/wY4UXExGBu+UCzzP/6sQRpBiPFgmqPTytrDo/gsUGqjOudLiHQcMU+uunULYQxVghC syiRa+UVlsKmx1hsEg== Date: Tue, 16 Apr 2019 20:02:39 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190416180158.112309-3-borntraeger@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19041618-0020-0000-0000-00000330844B X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19041618-0021-0000-0000-00002182CA7C Message-Id: <60692984-7a70-8b10-d51a-28fd019d3a88@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-16_07:,, 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904160115 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org FWiw, this patch need 5.1-rc3 or later. On 16.04.19 20:01, Christian Borntraeger wrote: > We do track the current steal time of the host CPUs. Let us use > this value to disable halt polling if the steal time goes beyond > a configured value. > > Signed-off-by: Christian Borntraeger > Acked-by: Paolo Bonzini > --- > arch/s390/include/asm/kvm_host.h | 1 + > arch/s390/kvm/Kconfig | 1 + > arch/s390/kvm/kvm-s390.c | 17 +++++++++++++++++ > 3 files changed, 19 insertions(+) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index e70f6ce14267..dbe254847e0d 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -313,6 +313,7 @@ struct kvm_vcpu_stat { > u64 halt_successful_poll; > u64 halt_attempted_poll; > u64 halt_poll_invalid; > + u64 halt_no_poll_steal; > u64 halt_wakeup; > u64 instruction_lctl; > u64 instruction_lctlg; > diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig > index 767453faacfc..e987e73738b5 100644 > --- a/arch/s390/kvm/Kconfig > +++ b/arch/s390/kvm/Kconfig > @@ -31,6 +31,7 @@ config KVM > select HAVE_KVM_IRQFD > select HAVE_KVM_IRQ_ROUTING > select HAVE_KVM_INVALID_WAKEUPS > + select HAVE_KVM_NO_POLL > select SRCU > select KVM_VFIO > ---help--- > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index d7423fdf5f68..8d0e2416f905 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -75,6 +75,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > { "halt_successful_poll", VCPU_STAT(halt_successful_poll) }, > { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) }, > { "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) }, > + { "halt_no_poll_steal", VCPU_STAT(halt_no_poll_steal) }, > { "halt_wakeup", VCPU_STAT(halt_wakeup) }, > { "instruction_lctlg", VCPU_STAT(instruction_lctlg) }, > { "instruction_lctl", VCPU_STAT(instruction_lctl) }, > @@ -182,6 +183,11 @@ static int hpage; > module_param(hpage, int, 0444); > MODULE_PARM_DESC(hpage, "1m huge page backing support"); > > +/* maximum percentage of steal time for polling */ > +static u8 halt_poll_max_steal = 10; > +module_param(halt_poll_max_steal, byte, 0644); > +MODULE_PARM_DESC(hpage, "Maximum percentage of steal time to allow pollinh"); > + > /* > * For now we handle at most 16 double words as this is what the s390 base > * kernel handles and stores in the prefix page. If we ever need to go beyond > @@ -3150,6 +3156,17 @@ static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start, > } > } > > +bool kvm_arch_no_poll(struct kvm_vcpu *vcpu) > +{ > + /* do not poll with more than halt_poll_max_steal percent of steal time */ > + if (S390_lowcore.avg_steal_timer * 100 / (TICK_USEC << 12) >= > + halt_poll_max_steal) { > + vcpu->stat.halt_no_poll_steal++; > + return true; > + } > + return false; > +} > + > int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) > { > /* kvm common code refers to this, but never calls it */ >