Quoting Kuo-Hsin Yang (2018-12-14 10:09:11) > On Fri, Dec 14, 2018 at 5:51 PM Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > > Quoting Kuo-Hsin Yang (2018-12-14 09:33:19) > > > On Fri, Dec 14, 2018 at 4:59 PM Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > > > > > Do you have a driver in mind (msm?) to demonstrate the use case? > > > > > > On Samsung Chromebook Plus, the drm/rockchip driver may call > > > rockchip_gem_get_pages()/drm_gem_get_pages() to pin a lot of pages, > > > breaking the page reclaim mechanism and causing oom-killer invocation. > > > > Hmm, but this doesn't change the unavailability of the pages, just how > > much work the shrinker must do scanning the evictable lists containing > > GEM pages to no avail. So it won't prevent an oom by itself because > > rockchip will still be holding the pages. > > > > Or? > > When the size of a zone is 4GB, the inactive_ratio is 5. If all pages > in the inactive_anon are pinned and active_anon / inactive_anon < 5, > page reclaim would only scan inactive_anon due to inactive_ratio. It > breaks page reclaim when the rockchip driver only pins about 1/6 of > the anon lru pages. If the pinned pages are marked unevictable, the > oom-killer would be invoked when anon lru is close to 0. Ta, I did not know of that relationship. Perfect details for the changelog to explain how this does improve page reclaim even in the absence of a GEM shrinker. :) -Chris _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
