Messages in this thread | | | Date | Mon, 5 Nov 2018 14:02:09 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH v4] mm, drm/i915: mark pinned shmemfs pages as unevictable |
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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.
> Cc: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Dave Hansen <dave.hansen@intel.com> > Signed-off-by: Kuo-Hsin Yang <vovoy@chromium.org>
other than that Acked-by: Michal Hocko <mhocko@suse.com>
[...]
> @@ -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.
> + * @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.
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
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