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. Stefan
