On Mon, Mar 04, 2019 at 03:11:05PM -0800, John Hubbard wrote: > get_user_page(): increments page->_refcount by a large amount (1024) > > put_user_page(): decrements page->_refcount by a large amount (1024) > > ...and just stop doing the odd (to me) technique of incrementing once for > each tail page. I cannot see any reason why that's actually required, as > opposed to just "raise the page->_refcount enough to avoid losing the head > page too soon". I'd very much like to see this in the infiniband umem code - the extra work and cost of touching every page in a huge page is very much undesired. Jason
