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Subject: Re: [PATCH] virtio_blk: set the default scheduler to none
From:   Li Feng <fengli@smartx.com>
In-Reply-To: <CACGkMEt4_T5-aArkS4LOQsndwrMkjm_K-uPjdFnNRvwknQPaPg@mail.gmail.com>
Date:   Thu, 7 Dec 2023 14:32:43 +0800
Cc:     Jens Axboe <axboe@kernel.dk>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        "open list:BLOCK LAYER" <linux-block@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        "open list:VIRTIO BLOCK AND SCSI DRIVERS" 
        <virtualization@lists.linux.dev>
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Message-Id: <ABA117F8-58AA-40EC-B3DA-4AB000A72BAD@smartx.com>
References: <20231207043118.118158-1-fengli@smartx.com>
 <CACGkMEt4_T5-aArkS4LOQsndwrMkjm_K-uPjdFnNRvwknQPaPg@mail.gmail.com>
To:     Jason Wang <jasowang@redhat.com>
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> On Dec 7, 2023, at 14:02, Jason Wang <jasowang@redhat.com> wrote:
>=20
> On Thu, Dec 7, 2023 at 12:33=E2=80=AFPM Li Feng <fengli@smartx.com> =
wrote:
>>=20
>> virtio-blk is generally used in cloud computing scenarios, where the
>> performance of virtual disks is very important. The mq-deadline =
scheduler
>> has a big performance drop compared to none with single queue.
>=20
> At least you can choose the scheduler based on if mq is supported or =
not?
>=20
> Thanks
>=20
The "none" scheduler has better performance regardless of whether it is
a single queue or multiple queues. Why not set the single queue =
scheduler
to none by default?

Thanks.