On Wed, Jun 22, 2011 at 1:01 PM, Anthony Liguori <anth...@codemonkey.ws> wrote: > On 05/22/2011 07:00 AM, Shribman, Aidan wrote: >> >> Subject: [PATCH] XBRLE page delta compression for live migration of large >> memory apps >> From: Aidan Shribman<aidan.shrib...@sap.com> >> >> By using XBRLE (Xor Based Run-Length-Encoding) we can reduce required >> bandwidth for transfering of dirty memory pages during live migration >> migrate_set_cachesize<size> >> migrate -x<url> >> Qemu host: Ubuntu 10.10 >> Testing: live migration (w and w/o XBRLE) tested successfully. > > By how much? > > This is a change to the live migration protocol, it would also require > documentation and an understanding of how it affects compatibility. > > The patch really needs to be split into logical pieces too. It's a bit too > big for a meaningful review.
Two places where you could consider splitting the patch is the caching and the sampling. Are they necessary for correctness and could they be submitted as follow-up patches to a core patch which does just the XBRLE? Also, whenever there are heuristics and use of floating point then there is some magic going on. It may be necessary and give a huge performance boost but needs explanation so it is not a black box or fragile mechanism once it has been merged upstream. Stefan
