On Mon, Nov 5, 2018 at 9:02 PM Michal Hocko <mhocko@xxxxxxxxxx> 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. > > Just a nit below > > > This patch was inspired by Chris Wilson's change [1]. > > > > [1]: https://patchwork.kernel.org/patch/9768741/ > > I would recommend using msg-id based url. I didn't find a msg-id based url for the [1] patch. This patch is sent to intel-gfx@xxxxxxxxxxxxxxxxxxxxx and linux-mm@xxxxxxxxx, but not to linux-kernel@xxxxxxxxxxxxxxx . > > > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Michal Hocko <mhocko@xxxxxxxx> > > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Cc: Dave Hansen <dave.hansen@xxxxxxxxx> > > Signed-off-by: Kuo-Hsin Yang <vovoy@xxxxxxxxxxxx> > > other than that > Acked-by: Michal Hocko <mhocko@xxxxxxxx> > > [...] > > > @@ -4184,15 +4185,13 @@ int page_evictable(struct page *page) > > > > #ifdef CONFIG_SHMEM > > /** > > - * check_move_unevictable_pages - check pages for evictability and move to appropriate zone lru list > > - * @pages: array of pages to check > > - * @nr_pages: number of pages to check > > + * check_move_unevictable_pages - move evictable pages to appropriate evictable > > + * lru lists > > I am not sure this is an improvement. I would just keep the original > wording. It is not great either but the explicit note about check for > evictability sounds like a better fit to me. OK, will keep the original wording. > > > + * @pvec: pagevec with pages to check > > * > > - * Checks pages for evictability and moves them to the appropriate lru list. > > - * > > - * This function is only used for SysV IPC SHM_UNLOCK. > > + * This function is only used to move shmem pages. > > I do not really see anything that would be shmem specific here. We can > use this function for any LRU pages unless I am missing something > obscure. I would just drop the last sentence. OK, this function should not be specific to shmem pages. Is it OK to remove the #ifdef SHMEM surrounding check_move_unevictable_pages? > > A note that this function should be only used for LRU pages would be > nice. > > > */ > > -void check_move_unevictable_pages(struct page **pages, int nr_pages) > > +void check_move_unevictable_pages(struct pagevec *pvec) > > { > > struct lruvec *lruvec; > > struct pglist_data *pgdat = NULL; > > @@ -4200,8 +4199,8 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages) > > int pgrescued = 0; > > int i; > > > > - for (i = 0; i < nr_pages; i++) { > > - struct page *page = pages[i]; > > + for (i = 0; i < pvec->nr; i++) { > > + struct page *page = pvec->pages[i]; > > struct pglist_data *pagepgdat = page_pgdat(page); > > > > pgscanned++; > > @@ -4233,4 +4232,5 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages) > > spin_unlock_irq(&pgdat->lru_lock); > > } > > } > > +EXPORT_SYMBOL(check_move_unevictable_pages); > > #endif /* CONFIG_SHMEM */ > > -- > > 2.19.1.930.g4563a0d9d0-goog > > > > -- > Michal Hocko > SUSE Labs
