From 0191de8772756163d7e92ab8b947a6df27995688 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 3 Jun 2020 16:02:11 -0700 Subject: [PATCH 2343/2944] mm: memcontrol: prepare swap controller setup for integration task #30476868 commit eccb52e7880973f221ab2606e4d22ce04d96a1a9 upstream A few cleanups to streamline the swap controller setup: - Replace the do_swap_account flag with cgroup_memory_noswap. This brings it in line with other functionality that is usually available unless explicitly opted out of - nosocket, nokmem. - Remove the really_do_swap_account flag that stores the boot option and is later used to switch the do_swap_account. It's not clear why this indirection is/was necessary. Use do_swap_account directly. - Minor coding style polishing In addition, memcg_meminfo and memcg_oom will still use do_swap_account, hence just need to be replaced. Signed-off-by: Johannes Weiner Signed-off-by: Andrew Morton Reviewed-by: Joonsoo Kim Cc: Alex Shi Cc: Hugh Dickins Cc: "Kirill A. Shutemov" Cc: Michal Hocko Cc: Roman Gushchin Cc: Shakeel Butt Cc: Balbir Singh Link: http://lkml.kernel.org/r/20200508183105.225460-15-hannes@cmpxchg.org Signed-off-by: Linus Torvalds Signed-off-by: zhongjiang-ali Reviewed-by: Xunlei Pang --- include/linux/memcontrol.h | 2 +- mm/memcontrol.c | 61 ++++++++++++++++++++++------------------------ mm/swap_cgroup.c | 4 +-- 3 files changed, 32 insertions(+), 35 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index cca7400..5c96261 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -633,7 +633,7 @@ struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, void mem_cgroup_print_oom_group(struct mem_cgroup *memcg); #ifdef CONFIG_MEMCG_SWAP -extern int do_swap_account; +extern bool cgroup_memory_noswap; #endif struct mem_cgroup *lock_page_memcg(struct page *page); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7143d92..64975f9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -98,17 +98,21 @@ /* Whether the swap controller is active */ #ifdef CONFIG_MEMCG_SWAP -int do_swap_account __read_mostly; +#ifdef CONFIG_MEMCG_SWAP_ENABLED +bool cgroup_memory_noswap __read_mostly; #else -#define do_swap_account 0 -#endif +bool cgroup_memory_noswap __read_mostly = 1; +#endif /* CONFIG_MEMCG_SWAP_ENABLED */ +#else +#define cgroup_memory_noswap 1 +#endif /* CONFIG_MEMCG_SWAP */ static struct workqueue_struct *memcg_wmark_wq; /* Whether legacy memory+swap accounting is active */ static bool do_memsw_account(void) { - return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account; + return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_noswap; } static const char *const mem_cgroup_lru_names[] = { @@ -1634,7 +1638,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { unsigned long nr; - if (memcg1_stats[i] == MEMCG_SWAP && !do_swap_account) + if (memcg1_stats[i] == MEMCG_SWAP && cgroup_memory_noswap) continue; nr = memcg_page_state_local(iter, memcg1_stats[i]); #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -7647,18 +7651,19 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask, /* * Every swap fault against a single page tries to charge the * page, bail as early as possible. shmem_unuse() encounters - * already charged pages, too. The USED bit is protected by - * the page lock, which serializes swap cache removal, which + * already charged pages, too. page->mem_cgroup is protected + * by the page lock, which serializes swap cache removal, which * in turn serializes uncharging. */ VM_BUG_ON_PAGE(!PageLocked(page), page); if (compound_head(page)->mem_cgroup) goto out; - if (do_swap_account) { + if (!cgroup_memory_noswap) { swp_entry_t ent = { .val = page_private(page), }; - unsigned short id = lookup_swap_cgroup_id(ent); + unsigned short id; + id = lookup_swap_cgroup_id(ent); rcu_read_lock(); memcg = mem_cgroup_from_id(id); if (memcg && !css_tryget_online(&memcg->css)) @@ -8228,7 +8233,7 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry) struct mem_cgroup *memcg; unsigned short oldid; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || !do_swap_account) + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) || cgroup_memory_noswap) return 0; memcg = page->mem_cgroup; @@ -8272,7 +8277,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) struct mem_cgroup *memcg; unsigned short id; - if (!do_swap_account) + if (cgroup_memory_noswap) return; id = swap_cgroup_record(entry, 0, nr_pages); @@ -8295,7 +8300,7 @@ long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) { long nr_swap_pages = get_nr_swap_pages(); - if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) return nr_swap_pages; for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) nr_swap_pages = min_t(long, nr_swap_pages, @@ -8312,7 +8317,7 @@ bool mem_cgroup_swap_full(struct page *page) if (vm_swap_full()) return true; - if (!do_swap_account || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) return false; memcg = page->mem_cgroup; @@ -8330,22 +8335,15 @@ bool mem_cgroup_swap_full(struct page *page) return false; } -/* for remember boot option*/ -#ifdef CONFIG_MEMCG_SWAP_ENABLED -static int really_do_swap_account __initdata = 1; -#else -static int really_do_swap_account __initdata; -#endif - -static int __init enable_swap_account(char *s) +static int __init setup_swap_account(char *s) { if (!strcmp(s, "1")) - really_do_swap_account = 1; + cgroup_memory_noswap = 0; else if (!strcmp(s, "0")) - really_do_swap_account = 0; + cgroup_memory_noswap = 1; return 1; } -__setup("swapaccount=", enable_swap_account); +__setup("swapaccount=", setup_swap_account); static u64 swap_current_read(struct cgroup_subsys_state *css, struct cftype *cft) @@ -8462,7 +8460,7 @@ static int swap_events_show(struct seq_file *m, void *v) { } /* terminate */ }; -static struct cftype memsw_cgroup_files[] = { +static struct cftype memsw_files[] = { { .name = "memsw.usage_in_bytes", .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), @@ -8491,13 +8489,12 @@ static int swap_events_show(struct seq_file *m, void *v) static int __init mem_cgroup_swap_init(void) { - if (!mem_cgroup_disabled() && really_do_swap_account) { - do_swap_account = 1; - WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, - swap_files)); - WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, - memsw_cgroup_files)); - } + if (mem_cgroup_disabled() || cgroup_memory_noswap) + return 0; + + WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); + WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); + return 0; } subsys_initcall(mem_cgroup_swap_init); diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c index 45affae..7aa764f 100644 --- a/mm/swap_cgroup.c +++ b/mm/swap_cgroup.c @@ -171,7 +171,7 @@ int swap_cgroup_swapon(int type, unsigned long max_pages) unsigned long length; struct swap_cgroup_ctrl *ctrl; - if (!do_swap_account) + if (cgroup_memory_noswap) return 0; length = DIV_ROUND_UP(max_pages, SC_PER_PAGE); @@ -209,7 +209,7 @@ void swap_cgroup_swapoff(int type) unsigned long i, length; struct swap_cgroup_ctrl *ctrl; - if (!do_swap_account) + if (cgroup_memory_noswap) return; mutex_lock(&swap_cgroup_mutex); -- 1.8.3.1