> -----Original Message----- > From: Christoph Hellwig [mailto:hch@xxxxxxxxxxxxx] > Sent: Friday, October 26, 2018 4:27 PM > To: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>; Daniel Verkamp > <dverkamp@xxxxxxxxxxxx>; Jens Axboe <axboe@xxxxxxxxx>; Michael S. Tsirkin > <mst@xxxxxxxxxx>; virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux- > block@xxxxxxxxxxxxxxx; Stefan Hajnoczi <stefanha@xxxxxxxxxx>; Liu, Changpeng > <changpeng.liu@xxxxxxxxx> > Subject: Re: [PATCH v8] virtio_blk: add discard and write zeroes support > > On Fri, Oct 26, 2018 at 01:28:54AM +0200, Paolo Bonzini wrote: > > On 15/10/2018 11:27, Christoph Hellwig wrote: > > > There is some issues in this spec. For one using the multiple ranges > > > also for write zeroes is rather inefficient. Write zeroes really should > > > use the same format as read and write. > > > > What makes it inefficient? > > We require a memory allocation for each write zeroes instead of encoding > the lba/len in the command. Make sense to me, but need to change the spec first.
