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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=unavailable 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 12E01C55192 for ; Thu, 23 Apr 2020 11:12:10 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 C31FF2077D for ; Thu, 23 Apr 2020 11:12:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C31FF2077D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 497F4l2zcnzDr7n for ; Thu, 23 Apr 2020 21:12:07 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=115.124.30.54; helo=out30-54.freemail.mail.aliyun.com; envelope-from=tianjia.zhang@linux.alibaba.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.alibaba.com Received: from out30-54.freemail.mail.aliyun.com (out30-54.freemail.mail.aliyun.com [115.124.30.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 497Dnv2sNCzDr0P for ; Thu, 23 Apr 2020 20:59:14 +1000 (AEST) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R741e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01f04427; MF=tianjia.zhang@linux.alibaba.com; NM=1; PH=DS; RN=36; SR=0; TI=SMTPD_---0TwQ1hHs_1587639532; Received: from 30.27.118.66(mailfrom:tianjia.zhang@linux.alibaba.com fp:SMTPD_---0TwQ1hHs_1587639532) by smtp.aliyun-inc.com(127.0.0.1); Thu, 23 Apr 2020 18:58:54 +0800 Subject: Re: [PATCH v2 1/7] KVM: s390: clean up redundant 'kvm_run' parameters To: Cornelia Huck References: <20200422125810.34847-1-tianjia.zhang@linux.alibaba.com> <20200422125810.34847-2-tianjia.zhang@linux.alibaba.com> <20200422154543.2efba3dd.cohuck@redhat.com> <20200422180403.03f60b0c.cohuck@redhat.com> <5e1e126d-f1b0-196c-594b-4289d0afb9a8@linux.alibaba.com> <20200423123901.72a4c6a4.cohuck@redhat.com> From: Tianjia Zhang Message-ID: <71344f73-c34f-a373-49d1-5d839c6be5f6@linux.alibaba.com> Date: Thu, 23 Apr 2020 18:58:52 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200423123901.72a4c6a4.cohuck@redhat.com> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wanpengli@tencent.com, kvm@vger.kernel.org, david@redhat.com, heiko.carstens@de.ibm.com, peterx@redhat.com, linux-mips@vger.kernel.org, hpa@zytor.com, kvmarm@lists.cs.columbia.edu, linux-s390@vger.kernel.org, frankja@linux.ibm.com, maz@kernel.org, joro@8bytes.org, x86@kernel.org, Christian Borntraeger , mingo@redhat.com, julien.thierry.kdev@gmail.com, thuth@redhat.com, gor@linux.ibm.com, suzuki.poulose@arm.com, kvm-ppc@vger.kernel.org, bp@alien8.de, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, jmattson@google.com, tsbogend@alpha.franken.de, christoffer.dall@arm.com, sean.j.christopherson@intel.com, linux-kernel@vger.kernel.org, james.morse@arm.com, pbonzini@redhat.com, vkuznets@redhat.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 2020/4/23 18:39, Cornelia Huck wrote: > On Thu, 23 Apr 2020 11:01:43 +0800 > Tianjia Zhang wrote: > >> On 2020/4/23 0:04, Cornelia Huck wrote: >>> On Wed, 22 Apr 2020 17:58:04 +0200 >>> Christian Borntraeger wrote: >>> >>>> On 22.04.20 15:45, Cornelia Huck wrote: >>>>> On Wed, 22 Apr 2020 20:58:04 +0800 >>>>> Tianjia Zhang wrote: >>>>> >>>>>> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu' >>>>>> structure. Earlier than historical reasons, many kvm-related function >>>>> >>>>> s/Earlier than/For/ ? >>>>> >>>>>> parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. >>>>>> This patch does a unified cleanup of these remaining redundant parameters. >>>>>> >>>>>> Signed-off-by: Tianjia Zhang >>>>>> --- >>>>>> arch/s390/kvm/kvm-s390.c | 37 ++++++++++++++++++++++--------------- >>>>>> 1 file changed, 22 insertions(+), 15 deletions(-) >>>>>> >>>>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>>>>> index e335a7e5ead7..d7bb2e7a07ff 100644 >>>>>> --- a/arch/s390/kvm/kvm-s390.c >>>>>> +++ b/arch/s390/kvm/kvm-s390.c >>>>>> @@ -4176,8 +4176,9 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) >>>>>> return rc; >>>>>> } >>>>>> >>>>>> -static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) >>>>>> +static void sync_regs_fmt2(struct kvm_vcpu *vcpu) >>>>>> { >>>>>> + struct kvm_run *kvm_run = vcpu->run; >>>>>> struct runtime_instr_cb *riccb; >>>>>> struct gs_cb *gscb; >>>>>> >>>>>> @@ -4235,7 +4236,7 @@ static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) >>>>>> } >>>>>> if (vcpu->arch.gs_enabled) { >>>>>> current->thread.gs_cb = (struct gs_cb *) >>>>>> - &vcpu->run->s.regs.gscb; >>>>>> + &kvm_run->s.regs.gscb; >>>>> >>>>> Not sure if these changes (vcpu->run-> => kvm_run->) are really worth >>>>> it. (It seems they amount to at least as much as the changes advertised >>>>> in the patch description.) >>>>> >>>>> Other opinions? >>>> >>>> Agreed. It feels kind of random. Maybe just do the first line (move kvm_run from the >>>> function parameter list into the variable declaration)? Not sure if this is better. >>>> >>> >>> There's more in this patch that I cut... but I think just moving >>> kvm_run from the parameter list would be much less disruptive. >>> >> >> I think there are two kinds of code(`vcpu->run->` and `kvm_run->`), but >> there will be more disruptive, not less. > > I just fail to see the benefit; sure, kvm_run-> is convenient, but the > current code is just fine, and any rework should be balanced against > the cost (e.g. cluttering git annotate). > cluttering git annotate ? Does it mean Fix xxxx ("comment"). Is it possible to solve this problem by splitting this patch?