Re: [Qemu-devel] [PATCH 0/6] migration: differentiate between pages and bytes

[Li, Liang Z]

> Current migration code returns number of bytes transferred and from there
> we decide if we.have sent something or not.  Problem, we need two results:
> number of pages written, and number of bytes written (depending on
> compression, zero pages, etc, it is not possible to derive one value from the
> other).
> 
> So, I changed all relevant function to return the number of written pages,
> and then pass as uint64_t *bytes_transferred to update the written bytes.
> 
> On current code, makes things a bit easier to understand, but is not strictely
> necesary.  But for the compression patches from Li, it makes a big difference,
> we can return that we have written a page, even if we have just started the
> write, but having writtten in reality zero bytes.
> 
> Once there, I add doxygen documentation to all function that I touched (yes,
> I was long due).
> 
> save_block_hdr really saved headers for pages, not blocks.  Rename it, and
> simplify the interface.
> 
> Li, does this make your life easier?  I hope so.  Should make really easy to
> remove the one_bytes_sent "hack", and allow my other suggestions.
> 
> Comments?
> 
> Later, Juan.
> 
> PD.  Code is obviously correct, but I run it through virt-test
>      anyways.  And it failed :-(  In despair, I tried virt-test on HEAD,
>      and it also failed, so ....  I add another thing to my ToDo list.
> 
> PD2.  Modifying ram_save_page() has become complicated, very
>       complicated. I think that know a couple of simplications, but
>       require touching RDMA code, and anyways, fixing migration in
>       "master" looks like a higher priority.

Hi Juan, when could you make your patches be merged?  I have prepared my 
Version 6 patches,  and I am waiting for your patches being merged before I can
send out my patches.

Liang