On 8/28/22 05:40, Bagas Sanjaya wrote: > Zero copy > --------- > > -Wrt. zero copy support, it is one generic requirement for nbd, fuse or > -similar drivers, one problem Xiaoguang mentioned is that pages mapped to > -userspace can't be remapped any more in kernel with existed mm interfaces, > -and it can be involved when submitting direct IO to /dev/ublkb*. Also > -Xiaoguang reported that big request may benefit from zero copy a lot, > -such as >= 256KB IO. > +Wrt. zero copy support, which is a generic requirement for nbd, fuse or > +similar drivers, a problem Xiaoguang mentioned is that pages mapped to > +userspace can't be remapped any more in kernel with existing mm interfaces. > +This can occurs when destining direct IO to ``/dev/ublkb*``. Also > +he reported that big requests (>= 256 KB IO) may benefit a lot from zero copy. I suggest eliminating "Wrt." also. -- ~Randy
