On Wed, Dec 12, 2018 at 08:22:37AM -0700, Jens Axboe wrote:
> That one is a little worse, since we only need a full page if we
> use all 256 segments. I don't want to make the fast case of
> 16 bytes single segment allocs get a full page, so we have to
> track if we used kmalloc() or mempool_alloc() for this particular
> range.
>
> I guess I could abuse ->end_io for that, set it if we end up
> punting to mempool. I'll do that.
How about a full emergency page hanging off struct nvme_ctrl,
and then in the completion path we can do:
if (req->special_vec.bv_page == ctrl->discard_emergency_page)
// clear some bit in ctrl->flags
else
kfree(page_address(req->special_vec.bv_page) +
