Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
 format=flowed
Content-Transfer-Encoding: 7bit
Date:   Tue, 10 Mar 2020 13:16:53 +0000
From:   Marc Zyngier <maz@kernel.org>
To:     zhukeqian <zhukeqian1@huawei.com>
Cc:     kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Jay Zhou <jianjay.zhou@huawei.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        James Morse <james.morse@arm.com>,
        Julien Thierry <julien.thierry.kdev@gmail.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: Re: [RFC] KVM: arm64: support enabling dirty log graually in small
 chunks
In-Reply-To: <64925c8b-af3d-beb5-bc9b-66ef1e47f92d@huawei.com>
References: <20200309085727.1106-1-zhukeqian1@huawei.com>
 <4b85699ec1d354cc73f5302560231f86@misterjones.org>
 <64925c8b-af3d-beb5-bc9b-66ef1e47f92d@huawei.com>
Message-ID: <a642a79ea9190542a9098e4c9dc5a9f2@kernel.org>
User-Agent: Roundcube Webmail/1.3.10
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 2020-03-10 08:26, zhukeqian wrote:
> Hi Marc,
> 
> On 2020/3/9 19:45, Marc Zyngier wrote:
>> Kegian,

[...]

>> Is there a userspace counterpart to it?
>> 
> As this KVM/x86 related changes have not been merged to mainline
> kernel, some little modification is needed on mainline Qemu.

Could you please point me to these changes?

> As I tested this patch on a 128GB RAM Linux VM with no huge pages, the
> time of enabling dirty log will decrease obviously.

I'm not sure how realistic that is. Not having huge pages tends to lead
to pretty bad performance in general...

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...