From: Fam Zheng <famz@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
Kevin Wolf <kwolf@redhat.com>, Ming Lei <ming.lei@canonical.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 5/9] virtio-blk: multiqueue batch notify
Date: Mon, 23 May 2016 16:56:05 +0800 [thread overview]
Message-ID: <20160523085605.GA13512@ad.usersys.redhat.com> (raw)
In-Reply-To: <9fbe1371-6244-0c09-af00-88f94c4a882b@redhat.com>
On Mon, 05/23 10:17, Paolo Bonzini wrote:
>
>
> On 23/05/2016 04:43, Fam Zheng wrote:
> > > The batch notification BH needs to know which virtqueues to notify when
> > > multiqueue is enabled. Use a bitmap to track the virtqueues that with
> > > pending notifications.
> >
> > This approach works great as long as VQs are in the same iothread. An
> > alternative way would be using separate BH per VQ, which will naturely work with
> > multi queue block layer in the future. Should we just go for that in the first
> > place? Seems less code churn, and no imaginable disadvantage compared to this
> > patch.
>
> It can be slower because all BHs are walked during aio_bh_poll, not just
> the scheduled ones.
>
OK, this is a fair point. Thanks.
Fam
next prev parent reply other threads:[~2016-05-23 8:56 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-20 23:40 [Qemu-devel] [PATCH 0/9] virtio-blk: multiqueue support Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 1/9] virtio-blk: use batch notify in non-dataplane case Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 2/9] virtio-blk: tell dataplane which vq to notify Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 3/9] virtio-blk: associate request with a virtqueue Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 4/9] virtio-blk: add VirtIOBlockConf->num_queues Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 5/9] virtio-blk: multiqueue batch notify Stefan Hajnoczi
2016-05-21 16:02 ` Paolo Bonzini
2016-05-27 21:38 ` Stefan Hajnoczi
2016-05-23 2:43 ` Fam Zheng
2016-05-23 8:17 ` Paolo Bonzini
2016-05-23 8:56 ` Fam Zheng [this message]
2016-05-20 23:40 ` [Qemu-devel] [PATCH 6/9] vmstate: add VMSTATE_VARRAY_UINT32_ALLOC Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 7/9] virtio-blk: live migrate s->rq with multiqueue Stefan Hajnoczi
2016-05-21 15:37 ` Paolo Bonzini
2016-05-27 21:42 ` Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 8/9] virtio-blk: dataplane multiqueue support Stefan Hajnoczi
2016-05-20 23:40 ` [Qemu-devel] [PATCH 9/9] virtio-blk: add num-queues device property Stefan Hajnoczi
2016-05-24 12:51 ` [Qemu-devel] [PATCH 0/9] virtio-blk: multiqueue support Christian Borntraeger
2016-05-27 21:44 ` Stefan Hajnoczi
2016-05-31 0:44 ` Stefan Hajnoczi
2016-05-27 11:55 ` [Qemu-devel] [RFC] virtio-blk: simple multithreaded MQ implementation for bdrv_raw Roman Pen
2016-05-27 22:27 ` Stefan Hajnoczi
2016-05-30 6:40 ` Alexandre DERUMIER
2016-05-30 12:14 ` Roman Penyaev
2016-05-30 11:59 ` Roman Penyaev
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