On Tue, Feb 09, 2021 at 02:01:26PM -0500, Johannes Weiner wrote: > alloc_page_buffers() currently uses get_mem_cgroup_from_page() for > charging the buffers to the page owner, which does an rcu-protected > page->memcg lookup and acquires a reference. But buffer allocation has > the page lock held throughout, which pins the page to the memcg and > thereby the memcg - neither rcu nor holding an extra reference during > the allocation are necessary. Use a raw page_memcg() instead. > > This was the last user of get_mem_cgroup_from_page(), delete it. > > Reported-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Thanks!
