If you mean the real huge page, this patch shouldn't have made a difference
because bio_vec->bv_offset is in [0, PAGE_SIZE), and iSer sets virt
boundary as 4K - 1.
However, things will change after multipage bvec is introduced.
Hi Ming,
I've received a blktrace from our customer showing the issue [1].
In this example trace they've submitted (contiguous) 64K I/Os and
without this patch, they're seeing a lot of splits as indicated by the
trace.
With the patch applied the I/O is directly issued to the LLDD without
the splits.
[1] http://beta.suse.com/private/jthumshirn/blktrace.txt
This patch makes sense to me. However I agree that we need to clarify
that this addresses cases where PAGE_SIZE-1 > queue_virt_boundary(q).
And also, lets replace "like iser" with "drivers that sets a virtual
boundary constraint" as nvme-rdma does the same thing.
