Re: [Qemu-devel] [PATCH] CPU consumption optimization of 'qemu-img convert' using bdrv_is_allocated()

[Stefan Hajnoczi]

On Wed, Jun 15, 2011 at 8:38 AM, Dmitry Konishchev <address@hidden> wrote:
> On Tue, Jun 14, 2011 at 7:58 PM, Stefan Hajnoczi <address@hidden> wrote:
>> Yes, please.
>
> OK, I'll do it as soon I'll find time for it.
>
>
> On Tue, Jun 14, 2011 at 7:58 PM, Stefan Hajnoczi <address@hidden> wrote:
>> For image files the block layer should be caching the device capacity (size)
>> anyway, so you probably don't need to allocate the array, just call
>> bdrv_get_geometry().  That might make it easier to write a self-contained
>> function.
>
> I've tried to not cache, but it turned out that bdrv_get_geometry()
> calls are quite noticeable in profiler without caching.

Why is bdrv_get_geometry() slow?

Stefan