On Mon, Nov 25, 2013 at 10:09:21PM -0800, Christoph Hellwig wrote: > > + q->bio_split = bioset_create(4, 0); > > + if (!q->bio_split) > > + goto fail_id; > > How did we arrive at a mempool size of 4 to make sure we can always make > progress with arbitrarily sized bios? Shouldn't we document the design > decision somewhere? It just has to be nonzero to guarantee forward progress - the bio_alloc_bioset() rescuer thing I did awhile back guarantees that. > > +static struct bio *blk_bio_discard_split(struct request_queue *q, > > + struct bio *bio, > > + struct bio_set *bs) > > +{ > > One fallout of this should be that it would allows us to impement > a range UNMAP/TRIP much more easily, which would help dramatically > with TRIM performance! Cool! -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel