Re: [Qemu-block] [PATCH 0/7] qcow2: Reduce the number of I/O ops when doing COW

[Alberto Garcia]

On Tue 23 May 2017 04:36:52 PM CEST, Eric Blake wrote:

>> here's a patch series that rewrites the copy-on-write code in the
>> qcow2 driver to reduce the number of I/O operations.
>
> And it competes with Denis and Anton's patches:
> https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg04547.html
>
> What plan of attack should we take on merging the best parts of these
> two series?

I took a look at that series and unless I overlooked something important
it seems that there's actually not that much overlap. Denis and Anton's
series deals with cluster preallocation and mine reduces the number of
I/O operations when there's a COW scenario. Most of my modifications are
in the peform_cow() function, but they barely touch that one.

I think we can review both separately, either of us can rebase our
series on top of the other, I don't expect big changes or conflicts.

Berto