Am 06.02.2012 16:50, schrieb Stefan Hajnoczi: > On Tue, Jan 24, 2012 at 3:16 PM, Kevin Wolf <kw...@redhat.com> wrote: >>> +/* >>> + * Efficiently zero a region of the disk image. Note that this is a >>> regular >>> + * I/O request like read or write and should have a reasonable size. This >>> + * function is not suitable for zeroing the entire image in a single >>> request. >>> + */ >> >> The reason for this is that in the fallback case you allocate memory for >> the whole request, right? So what about just limiting the allocation in >> bdrv_co_do_write_zeroes() to a reasonable size and putting a loop there >> for large requests? > > I'd rather not do that yet. We don't have a reasonable way to cancel > such a request yet. In the future, if we decide we'd like to do huge > bdrv_co_write_zeroes(), we could look at the details of making this > work.
Do we even need a way to cancel such requests? But anyway, include the reason in the comment, then we can leave it as it is. Kevin
