Re: [Qemu-devel] [PATCH 0/3] qcow2: Write complete sectors

[Dor Laor <dlaor@redhat.com>]

On 06/16/2009 12:31 PM, Kevin Wolf wrote:
> Once upon a time, there was a bdrv_pwrite that actually wrote single bytes to
> the file... However, today it is emulated by a read-modify-write cycle which
> aligns the request to sector size. This is slow. And we don't need it: qcow2
> often has the complete sector in memory, we don't need to read it from the disk
> again.
>
> These patches change the writes to L1 tables, L2 tables and refcount blocks to
> write complete sectors instead of single entries.
>
> This series depends on the qcow2 split to apply cleanly.
>
>    

If it's not an RFC, you better prepare a git tree for Anthony to pull from
and described how did you test it. Maybe committing the qemu-io scripts
would also be a move in the right direction.
Cheers,
Dor

> Kevin Wolf (3):
>    l2_allocate: Write complete sectors
>    alloc_cluster_link_l2: Write complete sectors
>    update_refcount: Write complete sectors
>
>   block/qcow2-cluster.c  |   61 +++++++++++++++++++++++++++++++++++++++++------
>   block/qcow2-refcount.c |   34 ++++++++++++++++++++------
>   2 files changed, 79 insertions(+), 16 deletions(-)
>
>
>
>