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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 4ACEBC433E0 for ; Thu, 14 May 2020 14:21:15 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2A0B92065D for ; Thu, 14 May 2020 14:21:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2A0B92065D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jZEjQ-0008NB-MH; Thu, 14 May 2020 14:21:04 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jZEjP-0008Mw-Mr for xen-devel@lists.xenproject.org; Thu, 14 May 2020 14:21:03 +0000 X-Inumbo-ID: 23f6d11c-95ee-11ea-b9cf-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 23f6d11c-95ee-11ea-b9cf-bc764e2007e4; Thu, 14 May 2020 14:21:03 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id CECB3AE52; Thu, 14 May 2020 14:21:04 +0000 (UTC) Subject: Re: [PATCH v2 2/3] xen/sched: don't call sync_vcpu_execstate() in sched_unit_migrate_finish() To: Jan Beulich References: <20200511112829.5500-1-jgross@suse.com> <20200511112829.5500-3-jgross@suse.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <6b6912d3-1bb1-ac3d-7fc7-a8d2a2f2db9b@suse.com> Date: Thu, 14 May 2020 16:21:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xenproject.org, George Dunlap , Dario Faggioli Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 14.05.20 15:57, Jan Beulich wrote: > On 11.05.2020 13:28, Juergen Gross wrote: >> With support of core scheduling sched_unit_migrate_finish() gained a >> call of sync_vcpu_execstate() as it was believed to be called as a >> result of vcpu migration in any case. >> >> In case of migrating a vcpu away from a physical cpu for a short period >> of time only this might not be true, so drop the call and let the lazy >> state syncing do its job. > > Replying here instead of on the patch 3 thread (and I'm sorry > for mixing up function names there): By saying "for a short > period of time only", do you imply without ever getting scheduled > on the new (temporary) CPU? If so, I think I understand this > change now, but then this could do with saying here. If not, I'm > afraid I'm still lost. I'll change the commit message to: ... for a short period of time only without ever being scheduled on the selected new cpu ... Juergen