| Message ID | 20210318110658.60892-3-songmuchun@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Use obj_cgroup APIs to charge kmem pages | expand |
On Thu, Mar 18, 2021 at 07:06:55PM +0800, Muchun Song wrote: > The page_memcg() is not suitable for use by page_expected_state() and > page_bad_reason(). Because it can BUG_ON() for the slab pages when > CONFIG_DEBUG_VM is enabled. As neither lru, nor kmem, nor slab page > should have anything left in there by the time the page is freed, what > we care about is whether the value of page->memcg_data is 0. So just > directly access page->memcg_data here. > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
On Thu, Mar 18, 2021 at 4:08 AM Muchun Song <songmuchun@bytedance.com> wrote: > > The page_memcg() is not suitable for use by page_expected_state() and > page_bad_reason(). Because it can BUG_ON() for the slab pages when > CONFIG_DEBUG_VM is enabled. As neither lru, nor kmem, nor slab page > should have anything left in there by the time the page is freed, what > we care about is whether the value of page->memcg_data is 0. So just > directly access page->memcg_data here. > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Shakeel Butt <shakeelb@google.com>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index f10966e3b4a5..e5454b85a106 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1124,7 +1124,7 @@ static inline bool page_expected_state(struct page *page, if (unlikely((unsigned long)page->mapping | page_ref_count(page) | #ifdef CONFIG_MEMCG - (unsigned long)page_memcg(page) | + page->memcg_data | #endif (page->flags & check_flags))) return false; @@ -1149,7 +1149,7 @@ static const char *page_bad_reason(struct page *page, unsigned long flags) bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; } #ifdef CONFIG_MEMCG - if (unlikely(page_memcg(page))) + if (unlikely(page->memcg_data)) bad_reason = "page still charged to cgroup"; #endif return bad_reason;
The page_memcg() is not suitable for use by page_expected_state() and page_bad_reason(). Because it can BUG_ON() for the slab pages when CONFIG_DEBUG_VM is enabled. As neither lru, nor kmem, nor slab page should have anything left in there by the time the page is freed, what we care about is whether the value of page->memcg_data is 0. So just directly access page->memcg_data here. Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- mm/page_alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)