Hi Jens, On Fri, Aug 11, 2017 at 08:26:59AM -0600, Jens Axboe wrote: > On 08/11/2017 04:46 AM, Christoph Hellwig wrote: > > On Wed, Aug 09, 2017 at 08:06:24PM -0700, Dan Williams wrote: > >> I like it, but do you think we should switch to sbvec[<constant>] to > >> preclude pathological cases where nr_pages is large? > > > > Yes, please. > > > > Then I'd like to see that the on-stack bio even matters for > > mpage_readpage / mpage_writepage. Compared to all the buffer head > > overhead the bio allocation should not actually matter in practice. > > I'm skeptical for that path, too. I also wonder how far we could go > with just doing a per-cpu bio recycling facility, to reduce the cost > of having to allocate a bio. The on-stack bio parts are fine for > simple use case, where simple means that the patch just special > cases the allocation, and doesn't have to change much else. > > I had a patch for bio recycling and batched freeing a year or two > ago, I'll see if I can find and resurrect it.
So, you want to go with per-cpu bio recycling approach to remove rw_page? So, do you want me to hold this patchset?
