From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932124AbbDIXxq (ORCPT ); Thu, 9 Apr 2015 19:53:46 -0400 Received: from mail-bn1on0138.outbound.protection.outlook.com ([157.56.110.138]:7615 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753284AbbDIXxn (ORCPT ); Thu, 9 Apr 2015 19:53:43 -0400 Message-ID: <1428623611.22867.561.camel@freescale.com> Subject: Re: [PATCH 0/2] powerpc/kvm: Enable running guests on RT Linux From: Scott Wood To: Purcareata Bogdan CC: Sebastian Andrzej Siewior , Paolo Bonzini , Alexander Graf , Bogdan Purcareata , , , , , Thomas Gleixner Date: Thu, 9 Apr 2015 18:53:31 -0500 In-Reply-To: <55262DD3.2050707@freescale.com> References: <1424251955-308-1-git-send-email-bogdan.purcareata@freescale.com> <54E73A6C.9080500@suse.de> <54E740E7.5090806@redhat.com> <54E74A8C.30802@linutronix.de> <1424734051.4698.17.camel@freescale.com> <54EF196E.4090805@redhat.com> <54EF2025.80404@linutronix.de> <1424999159.4698.78.camel@freescale.com> <55158E6D.40304@freescale.com> <1428016310.22867.289.camel@freescale.com> <551E4A41.1080705@freescale.com> <1428096375.22867.369.camel@freescale.com> <55262DD3.2050707@freescale.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.10-0ubuntu1~14.10.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [2601:2:5800:3f7:12bf:48ff:fe84:c9a0] X-ClientProxiedBy: BY2PR05CA046.namprd05.prod.outlook.com (10.141.250.36) To BLUPR03MB1474.namprd03.prod.outlook.com (25.163.81.16) Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=scottwood@freescale.com; X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:BLUPR03MB1474; X-Forefront-Antispam-Report: BMV:1;SFV:NSPM;SFS:(10019020)(979002)(6009001)(377424004)(24454002)(51704005)(47776003)(40100003)(103116003)(122386002)(33646002)(50986999)(36756003)(50466002)(93886004)(92566002)(46102003)(62966003)(5820100001)(86362001)(23676002)(87976001)(77156002)(76176999)(2950100001)(50226001)(110136001)(42186005)(99106002)(3826002)(969003)(989001)(999001)(1009001)(1019001);DIR:OUT;SFP:1102;SCL:1;SRVR:BLUPR03MB1474;H:[IPv6:2601:2:5800:3f7:12bf:48ff:fe84:c9a0];FPR:;SPF:None;MLV:ovrnspm;PTR:InfoNoRecords;LANG:en; X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(5002010)(5005006);SRVR:BLUPR03MB1474;BCL:0;PCL:0;RULEID:;SRVR:BLUPR03MB1474; X-Forefront-PRVS: 0541031FF6 X-OriginatorOrg: freescale.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Apr 2015 23:53:38.1718 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: BLUPR03MB1474 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2015-04-09 at 10:44 +0300, Purcareata Bogdan wrote: > So at this point I was getting kinda frustrated so I decided to measure > the time spend in kvm_mpic_write and kvm_mpic_read. I assumed these were > the main entry points in the in-kernel MPIC and were basically executed > while holding the spinlock. The scenario was the same - 24 VCPUs guest, > with 24 virtio+vhost interfaces, only this time I ran 24 ping flood > threads to another board instead of netperf. I assumed this would impose > a heavier stress. > > The latencies look pretty ok, around 1-2 us on average, with the max > shown below: > > .kvm_mpic_read 14.560 > .kvm_mpic_write 12.608 > > Those are also microseconds. This was run for about 15 mins. What about other entry points such as kvm_set_msi() and kvmppc_mpic_set_epr()? -Scott