From 5ccc5abaaf6f9242cc63342c5286990233f392fa Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Wed, 20 Jan 2016 15:03:10 -0800 Subject: mm: free swap cache aggressively if memcg swap is full Swap cache pages are freed aggressively if swap is nearly full (>50% currently), because otherwise we are likely to stop scanning anonymous when we near the swap limit even if there is plenty of freeable swap cache pages. We should follow the same trend in case of memory cgroup, which has its own swap limit. Signed-off-by: Vladimir Davydov Acked-by: Johannes Weiner Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index bcb38718e174..6a0007965e31 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5761,6 +5761,28 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) return nr_swap_pages; } +bool mem_cgroup_swap_full(struct page *page) +{ + struct mem_cgroup *memcg; + + VM_BUG_ON_PAGE(!PageLocked(page), page); + + if (vm_swap_full()) + return true; + if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return false; + + memcg = page->mem_cgroup; + if (!memcg) + return false; + + for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) + if (page_counter_read(&memcg->swap) * 2 >= memcg->swap.limit) + return true; + + return false; +} + /* for remember boot option*/ #ifdef CONFIG_MEMCG_SWAP_ENABLED static int really_do_swap_account __initdata = 1; -- cgit v1.2.3-70-g09d2