On Wed, Apr 06, 2016 at 10:37:05AM +0800, Ming Lei wrote: > On Wed, Apr 6, 2016 at 10:34 AM, Kent Overstreet > <kent.overstreet@xxxxxxxxx> wrote: > > On Wed, Apr 06, 2016 at 10:30:22AM +0800, Ming Lei wrote: > >> Now limit.max_segments is for limiting segments from hw view, one this > >> segment may include lots of pages/bvecs. > >> > >> The current bio_clone() issue is that we can't clone from one bio which > >> includes more than 256 bvecs, maybe all these 256 bvecs belong to > >> one same hw segment. > > > > So the distinction is purely a post multipage bvec thing? > > Even after multipage bvec is applied, the limit for max bvecs is still needed > for some cases like bio bounce, in which bio_clone() need to > clone single page bvec. s/max bvecs/max pages/? What I meant is that until we have multipage bvecs, unless I'm missing something max_segments is exactly what we want. After multipage bvecs, things do get more complicated I agree. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
