Re: [PATCH] mm/workingset: do not forget to unlock page

[Johannes Weiner]

On Wed, Feb 03, 2016 at 01:19:39PM -0800, Andrew Morton wrote:
> Yup.  I turned it into a fix against
> mm-workingset-per-cgroup-cache-thrash-detection.patch, which is where
> the bug was added.  And I did the goto thing instead, so the final
> result will be
> 
> void workingset_activation(struct page *page)
> {
> 	struct lruvec *lruvec;
> 
> 	lock_page_memcg(page);
> 	/*
> 	 * Filter non-memcg pages here, e.g. unmap can call
> 	 * mark_page_accessed() on VDSO pages.
> 	 *
> 	 * XXX: See workingset_refault() - this should return
> 	 * root_mem_cgroup even for !CONFIG_MEMCG.
> 	 */
> 	if (!mem_cgroup_disabled() && !page_memcg(page))
> 		goto out;
> 	lruvec = mem_cgroup_zone_lruvec(page_zone(page), page_memcg(page));
> 	atomic_long_inc(&lruvec->inactive_age);
> out:
> 	unlock_page_memcg(page);
> }

LGTM, thank you.