Since readahead page will be charged on memcg too. We don't need to check this exception now. Rmove them is safe as all user pages are charged before use.
Signed-off-by: Alex Shi <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] --- mm/memcontrol.c | 21 ++++----------------- 1 file changed, 4 insertions(+), 17 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e84c2b5596f2..9e44ae22d591 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1322,12 +1322,7 @@ struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct pglist_data *pgd } memcg = page->mem_cgroup; - /* - * Swapcache readahead pages are added to the LRU - and - * possibly migrated - before they are charged. - */ - if (!memcg) - memcg = root_mem_cgroup; + VM_BUG_ON_PAGE(!memcg, page); mz = mem_cgroup_page_nodeinfo(memcg, page); lruvec = &mz->lruvec; @@ -6897,10 +6892,8 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) if (newpage->mem_cgroup) return; - /* Swapcache readahead pages can get replaced before being charged */ memcg = oldpage->mem_cgroup; - if (!memcg) - return; + VM_BUG_ON_PAGE(!memcg, oldpage); /* Force-charge the new page. The old one will be freed soon */ nr_pages = thp_nr_pages(newpage); @@ -7094,10 +7087,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) return; memcg = page->mem_cgroup; - - /* Readahead page, never charged */ - if (!memcg) - return; + VM_BUG_ON_PAGE(!memcg, page); /* * In case the memcg owning these pages has been offlined and doesn't @@ -7158,10 +7148,7 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) return 0; memcg = page->mem_cgroup; - - /* Readahead page, never charged */ - if (!memcg) - return 0; + VM_BUG_ON_PAGE(!memcg, page); if (!entry.val) { memcg_memory_event(memcg, MEMCG_SWAP_FAIL); -- 1.8.3.1
