On Mon, Mar 15, 2021 at 10:06:40AM +0100, David Hildenbrand wrote: > > BTW, I stumbled yesterday over > > alloc_contig_pages()->pfn_range_valid_contig(): > > if (page_count(page) > 0) > rerurn false; > if (PageHuge(page)) > return false; > > As used by memtrace and for gigantic pages. We can now > > a) Drop these check completely, as it's best-effort only and racy. > alloc_contig_pages()/alloc_contig_range() will handle it properly. > > b) Similarly, check for gigantic pages and/or movability/migratability. > > Dropping both checks might be the right thing to do: might significantly > increase allocation chances -- as we actually end up migrating busy pages > ...
Oh, sorry David, my mail client tricked me and I did not see this till now. I will have a look, but I would like to collect some more feedback from all pieces before going any further and write a new version. Vlastimil patch#1 and patch#2 and he was ok with them, but let see what others think as well. -- Oscar Salvador SUSE L3
