From 7941d2145abc4def5583f9d8d0b2e02647b6d1de Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 14 Jan 2016 15:21:23 -0800 Subject: [PATCH] mm: memcontrol: do not account memory+swap on unified hierarchy The unified hierarchy memory controller doesn't expose the memory+swap counter to userspace, but its accounting is hardcoded in all charge paths right now, including the per-cpu charge cache ("the stock"). To avoid adding yet more pointless memory+swap accounting with the socket memory support in unified hierarchy, disable the counter altogether when in unified hierarchy mode. Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Reviewed-by: Vladimir Davydov Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 44 +++++++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 19 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 08ef3d2..6903e7d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -87,6 +87,12 @@ int do_swap_account __read_mostly; #define do_swap_account 0 #endif +/* Whether legacy memory+swap accounting is active */ +static bool do_memsw_account(void) +{ + return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account; +} + static const char * const mem_cgroup_stat_names[] = { "cache", "rss", @@ -1199,7 +1205,7 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) if (count < limit) margin = limit - count; - if (do_swap_account) { + if (do_memsw_account()) { count = page_counter_read(&memcg->memsw); limit = READ_ONCE(memcg->memsw.limit); if (count <= limit) @@ -1302,7 +1308,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) pr_cont(":"); for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { - if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) + if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account()) continue; pr_cont(" %s:%luKB", mem_cgroup_stat_names[i], K(mem_cgroup_read_stat(iter, i))); @@ -1925,7 +1931,7 @@ static void drain_stock(struct memcg_stock_pcp *stock) if (stock->nr_pages) { page_counter_uncharge(&old->memory, stock->nr_pages); - if (do_swap_account) + if (do_memsw_account()) page_counter_uncharge(&old->memsw, stock->nr_pages); css_put_many(&old->css, stock->nr_pages); stock->nr_pages = 0; @@ -2055,11 +2061,11 @@ retry: if (consume_stock(memcg, nr_pages)) return 0; - if (!do_swap_account || + if (!do_memsw_account() || page_counter_try_charge(&memcg->memsw, batch, &counter)) { if (page_counter_try_charge(&memcg->memory, batch, &counter)) goto done_restock; - if (do_swap_account) + if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, batch); mem_over_limit = mem_cgroup_from_counter(counter, memory); } else { @@ -2146,7 +2152,7 @@ force: * temporarily by force charging it. */ page_counter_charge(&memcg->memory, nr_pages); - if (do_swap_account) + if (do_memsw_account()) page_counter_charge(&memcg->memsw, nr_pages); css_get_many(&memcg->css, nr_pages); @@ -2183,7 +2189,7 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) return; page_counter_uncharge(&memcg->memory, nr_pages); - if (do_swap_account) + if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, nr_pages); css_put_many(&memcg->css, nr_pages); @@ -2469,7 +2475,7 @@ void __memcg_kmem_uncharge(struct page *page, int order) page_counter_uncharge(&memcg->kmem, nr_pages); page_counter_uncharge(&memcg->memory, nr_pages); - if (do_swap_account) + if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, nr_pages); page->mem_cgroup = NULL; @@ -3184,7 +3190,7 @@ static int memcg_stat_show(struct seq_file *m, void *v) BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { - if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) + if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account()) continue; seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i], mem_cgroup_read_stat(memcg, i) * PAGE_SIZE); @@ -3206,14 +3212,14 @@ static int memcg_stat_show(struct seq_file *m, void *v) } seq_printf(m, "hierarchical_memory_limit %llu\n", (u64)memory * PAGE_SIZE); - if (do_swap_account) + if (do_memsw_account()) seq_printf(m, "hierarchical_memsw_limit %llu\n", (u64)memsw * PAGE_SIZE); for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { unsigned long long val = 0; - if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) + if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account()) continue; for_each_mem_cgroup_tree(mi, memcg) val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE; @@ -3344,7 +3350,7 @@ static void mem_cgroup_threshold(struct mem_cgroup *memcg) { while (memcg) { __mem_cgroup_threshold(memcg, false); - if (do_swap_account) + if (do_memsw_account()) __mem_cgroup_threshold(memcg, true); memcg = parent_mem_cgroup(memcg); @@ -4497,7 +4503,7 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, * we call find_get_page() with swapper_space directly. */ page = find_get_page(swap_address_space(ent), ent.val); - if (do_swap_account) + if (do_memsw_account()) entry->val = ent.val; return page; @@ -4532,7 +4538,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma, page = find_get_entry(mapping, pgoff); if (radix_tree_exceptional_entry(page)) { swp_entry_t swp = radix_to_swp_entry(page); - if (do_swap_account) + if (do_memsw_account()) *entry = swp; page = find_get_page(swap_address_space(swp), swp.val); } @@ -5325,7 +5331,7 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, if (page->mem_cgroup) goto out; - if (do_swap_account) { + if (do_memsw_account()) { swp_entry_t ent = { .val = page_private(page), }; unsigned short id = lookup_swap_cgroup_id(ent); @@ -5399,7 +5405,7 @@ void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg, memcg_check_events(memcg, page); local_irq_enable(); - if (do_swap_account && PageSwapCache(page)) { + if (do_memsw_account() && PageSwapCache(page)) { swp_entry_t entry = { .val = page_private(page) }; /* * The swap entry might not get freed for a long time, @@ -5448,7 +5454,7 @@ static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, if (!mem_cgroup_is_root(memcg)) { page_counter_uncharge(&memcg->memory, nr_pages); - if (do_swap_account) + if (do_memsw_account()) page_counter_uncharge(&memcg->memsw, nr_pages); memcg_oom_recover(memcg); } @@ -5656,7 +5662,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) VM_BUG_ON_PAGE(PageLRU(page), page); VM_BUG_ON_PAGE(page_count(page), page); - if (!do_swap_account) + if (!do_memsw_account()) return; memcg = page->mem_cgroup; @@ -5696,7 +5702,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry) struct mem_cgroup *memcg; unsigned short id; - if (!do_swap_account) + if (!do_memsw_account()) return; id = swap_cgroup_record(entry, 0); -- 2.7.4