[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (d
From: |
Dave Hansen |
Subject: |
Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration |
Date: |
Thu, 15 Dec 2016 17:09:10 -0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 |
On 12/15/2016 04:48 PM, Li, Liang Z wrote:
>>> It seems we leave too many bit for the pfn, and the bits leave for
>>> length is not enough, How about keep 45 bits for the pfn and 19 bits
>>> for length, 45 bits for pfn can cover 57 bits physical address, that should
>>> be
>> enough in the near feature.
>>> What's your opinion?
>> I still think 'order' makes a lot of sense. But, as you say, 57 bits is
>> enough for
>> x86 for a while. Other architectures.... who knows?
Thinking about this some more... There are really only two cases that
matter: 4k pages and "much bigger" ones.
Squeezing each 4k page into 8 bytes of metadata helps guarantee that
this scheme won't regress over the old scheme in any cases. For bigger
ranges, 8 vs 16 bytes means *nothing*. And 16 bytes will be as good or
better than the old scheme for everything which is >4k.
How about this:
* 52 bits of 'pfn', 5 bits of 'order', 7 bits of 'length'
* One special 'length' value to mean "actual length in next 8 bytes"
That should be pretty simple to produce and decode. We have two record
sizes, but I think it is manageable.
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, (continued)
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/14
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Dave Hansen, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Michael S. Tsirkin, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Andrea Arcangeli, 2016/12/16
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/17
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration,
Dave Hansen <=
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Dave Hansen, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/15
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Andrea Arcangeli, 2016/12/16
- Re: [Qemu-devel] [PATCH kernel v5 0/5] Extend virtio-balloon for fast (de)inflating & fast live migration, Li, Liang Z, 2016/12/17