[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC 0/7] Migration stats
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [RFC 0/7] Migration stats |
Date: |
Mon, 13 Aug 2012 09:14:13 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 |
On 08/13/2012 09:08 AM, Juan Quintela wrote:
>>
>> Should we have some sort of stat for the number of pages that are sent
>> more than once, and/or for the maximum count of times that a given page
>> was sent? Having hot/cold page analysis might make it easier to decide
>> in the future which pages to avoid sending until the very end, and
>> knowing how many pages are sent multiple times as well as the maximum
>> times any one page is sent might help.
>
> That is not trivial to do without "duplicating" the bitmap. Bitmap is
> already quite big on machines with huge memory. Adding a field to show
> how many times a page have been sent sounds too much. Furthermore, how
> could this information could be used externally.
No big loss, then. I was just wondering out loud, and don't really have
a particular need for this information.
I guess with XBZRLE, you _do_ have a count of how many cache hits you
had, which is somewhat related (a cache hit implies sending a page more
than once).
--
Eric Blake address@hidden +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature