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From: Jason Wang <jasowang@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	peterx@redhat.com, virtualization@lists.linux-foundation.org,
	pbonzini@redhat.com
Subject: Re: [RFC PATCH V2 1/2] vhost: convert pre sorted vhost memory array to interval tree
Date: Thu, 28 Apr 2016 14:20:32 +0800	[thread overview]
Message-ID: <5721ABB0.8070509@redhat.com> (raw)
In-Reply-To: <20160427142948-mutt-send-email-mst@redhat.com>



On 04/27/2016 07:30 PM, Michael S. Tsirkin wrote:
> On Fri, Mar 25, 2016 at 10:34:33AM +0800, Jason Wang wrote:
>> > Current pre-sorted memory region array has some limitations for future
>> > device IOTLB conversion:
>> > 
>> > 1) need extra work for adding and removing a single region, and it's
>> >    expected to be slow because of sorting or memory re-allocation.
>> > 2) need extra work of removing a large range which may intersect
>> >    several regions with different size.
>> > 3) need trick for a replacement policy like LRU
>> > 
>> > To overcome the above shortcomings, this patch convert it to interval
>> > tree which can easily address the above issue with almost no extra
>> > work.
>> > 
>> > The patch could be used for:
>> > 
>> > - Extend the current API and only let the userspace to send diffs of
>> >   memory table.
>> > - Simplify Device IOTLB implementation.
> Does this affect performance at all?
>

In pktgen test, no difference.

Thanks

WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	peterx@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org
Subject: Re: [RFC PATCH V2 1/2] vhost: convert pre sorted vhost memory array to interval tree
Date: Thu, 28 Apr 2016 14:20:32 +0800	[thread overview]
Message-ID: <5721ABB0.8070509@redhat.com> (raw)
In-Reply-To: <20160427142948-mutt-send-email-mst@redhat.com>



On 04/27/2016 07:30 PM, Michael S. Tsirkin wrote:
> On Fri, Mar 25, 2016 at 10:34:33AM +0800, Jason Wang wrote:
>> > Current pre-sorted memory region array has some limitations for future
>> > device IOTLB conversion:
>> > 
>> > 1) need extra work for adding and removing a single region, and it's
>> >    expected to be slow because of sorting or memory re-allocation.
>> > 2) need extra work of removing a large range which may intersect
>> >    several regions with different size.
>> > 3) need trick for a replacement policy like LRU
>> > 
>> > To overcome the above shortcomings, this patch convert it to interval
>> > tree which can easily address the above issue with almost no extra
>> > work.
>> > 
>> > The patch could be used for:
>> > 
>> > - Extend the current API and only let the userspace to send diffs of
>> >   memory table.
>> > - Simplify Device IOTLB implementation.
> Does this affect performance at all?
>

In pktgen test, no difference.

Thanks

WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	peterx@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [RFC PATCH V2 1/2] vhost: convert pre sorted vhost memory array to interval tree
Date: Thu, 28 Apr 2016 14:20:32 +0800	[thread overview]
Message-ID: <5721ABB0.8070509@redhat.com> (raw)
In-Reply-To: <20160427142948-mutt-send-email-mst@redhat.com>



On 04/27/2016 07:30 PM, Michael S. Tsirkin wrote:
> On Fri, Mar 25, 2016 at 10:34:33AM +0800, Jason Wang wrote:
>> > Current pre-sorted memory region array has some limitations for future
>> > device IOTLB conversion:
>> > 
>> > 1) need extra work for adding and removing a single region, and it's
>> >    expected to be slow because of sorting or memory re-allocation.
>> > 2) need extra work of removing a large range which may intersect
>> >    several regions with different size.
>> > 3) need trick for a replacement policy like LRU
>> > 
>> > To overcome the above shortcomings, this patch convert it to interval
>> > tree which can easily address the above issue with almost no extra
>> > work.
>> > 
>> > The patch could be used for:
>> > 
>> > - Extend the current API and only let the userspace to send diffs of
>> >   memory table.
>> > - Simplify Device IOTLB implementation.
> Does this affect performance at all?
>

In pktgen test, no difference.

Thanks

  reply	other threads:[~2016-04-28  6:20 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-25  2:34 [RFC PATCH V2 0/2] basic device IOTLB support Jason Wang
2016-03-25  2:34 ` [Qemu-devel] " Jason Wang
2016-03-25  2:34 ` Jason Wang
2016-03-25  2:34 ` [RFC PATCH V2 1/2] vhost: convert pre sorted vhost memory array to interval tree Jason Wang
2016-03-25  2:34   ` [Qemu-devel] " Jason Wang
2016-03-25  2:34   ` Jason Wang
2016-04-27 11:30   ` Michael S. Tsirkin
2016-04-27 11:30     ` [Qemu-devel] " Michael S. Tsirkin
2016-04-27 11:30     ` Michael S. Tsirkin
2016-04-28  6:20     ` Jason Wang [this message]
2016-04-28  6:20       ` [Qemu-devel] " Jason Wang
2016-04-28  6:20       ` Jason Wang
2016-03-25  2:34 ` [RFC PATCH V2 2/2] vhost: device IOTLB API Jason Wang
2016-03-25  2:34   ` [Qemu-devel] " Jason Wang
2016-03-25  2:34   ` Jason Wang
2016-04-27 11:45   ` Michael S. Tsirkin
2016-04-27 11:45     ` [Qemu-devel] " Michael S. Tsirkin
2016-04-27 11:45     ` Michael S. Tsirkin
2016-04-28  6:37     ` Jason Wang
2016-04-28  6:37       ` [Qemu-devel] " Jason Wang
2016-04-28  6:37       ` Jason Wang
2016-04-28 14:43       ` Michael S. Tsirkin
2016-04-28 14:43         ` [Qemu-devel] " Michael S. Tsirkin
2016-04-28 14:43         ` Michael S. Tsirkin
2016-04-29  1:12         ` Jason Wang
2016-04-29  1:12           ` [Qemu-devel] " Jason Wang
2016-04-29  1:12           ` Jason Wang
2016-04-29  4:44           ` Jason Wang
2016-04-29  4:44             ` [Qemu-devel] " Jason Wang
2016-04-29  4:44             ` Jason Wang
2016-04-27 11:45   ` Michael S. Tsirkin

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