Re: [Qemu-devel] [PATCH v2 1/2] qcow2: Introduce an option for sufficient L2 cache for the entire image

[Eric Blake]

On 07/24/2018 12:02 PM, Leonid Bloch wrote:
> An option "l2-cache-full" is introduced to automatically set the qcow2
> L2 cache to a sufficient value for covering the entire image. The memory
> overhead when using this option is not big (1 MB for each 8 GB of
> virtual image size with the default cluster size) and it can noticeably
> improve performance when using large images with frequent I/O.
> Previously, for this functionality the correct L2 cache size needed to
> be calculated manually or with a script, and then this size needed to be
> passed to the "l2-cache-size" option. Now it is sufficient to just pass
> the boolean "l2-cache-full" option.
>
> Additionally, the documentation for the related options is fixed, and a
> small grammar fix is made in the immediate proximity of the changes.

Is it worth splitting the small grammar fix:


>       if (combined_cache_size_set) {
>           if (l2_cache_size_set && refcount_cache_size_set) {
>               error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE
>                          " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set 
> "
> -                       "the same time");
> +                       "at the same time");

into a standalone patch for application in 3.0, while the rest of this 
patch waits for 3.1?

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org