On Mon 05-11-18 14:02:09, Michal Hocko wrote: > On Mon 05-11-18 19:13:48, Kuo-Hsin Yang wrote: > > The i915 driver uses shmemfs to allocate backing storage for gem > > objects. These shmemfs pages can be pinned (increased ref count) by > > shmem_read_mapping_page_gfp(). When a lot of pages are pinned, vmscan > > wastes a lot of time scanning these pinned pages. In some extreme case, > > all pages in the inactive anon lru are pinned, and only the inactive > > anon lru is scanned due to inactive_ratio, the system cannot swap and > > invokes the oom-killer. Mark these pinned pages as unevictable to speed > > up vmscan. > > > > Export pagevec API check_move_unevictable_pages(). > > Thanks for reworking the patch. This looks much more to my taste. At > least the mm part. I haven't really looked at the the drm part. One side note. Longterm we probably want a better pinning API. It would hide this LRU manipulation implementation detail + enforce some limiting and provide a good way that the pin is longterm. People are working on this already but it is a PITA and long time to get there. -- Michal Hocko SUSE Labs
