diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 228 |
1 files changed, 223 insertions, 5 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 7d8eec2310cc..2f4be18b57cb 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -51,6 +51,7 @@ #include <linux/psi.h> #include <linux/pagewalk.h> #include <linux/shmem_fs.h> +#include <linux/ctype.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -3070,6 +3071,14 @@ static bool can_age_anon_pages(struct pglist_data *pgdat, #ifdef CONFIG_LRU_GEN +#ifdef CONFIG_LRU_GEN_ENABLED +DEFINE_STATIC_KEY_ARRAY_TRUE(lru_gen_caps, NR_LRU_GEN_CAPS); +#define get_cap(cap) static_branch_likely(&lru_gen_caps[cap]) +#else +DEFINE_STATIC_KEY_ARRAY_FALSE(lru_gen_caps, NR_LRU_GEN_CAPS); +#define get_cap(cap) static_branch_unlikely(&lru_gen_caps[cap]) +#endif + /****************************************************************************** * shorthand helpers ******************************************************************************/ @@ -3946,7 +3955,8 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long next, struct vm_area goto next; if (!pmd_trans_huge(pmd[i])) { - if (IS_ENABLED(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)) + if (IS_ENABLED(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG) && + get_cap(LRU_GEN_NONLEAF_YOUNG)) pmdp_test_and_clear_young(vma, addr, pmd + i); goto next; } @@ -4044,10 +4054,12 @@ restart: walk->mm_stats[MM_NONLEAF_TOTAL]++; #ifdef CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG - if (!pmd_young(val)) - continue; + if (get_cap(LRU_GEN_NONLEAF_YOUNG)) { + if (!pmd_young(val)) + continue; - walk_pmd_range_locked(pud, addr, vma, args, bitmap, &pos); + walk_pmd_range_locked(pud, addr, vma, args, bitmap, &pos); + } #endif if (!walk->force_scan && !test_bloom_filter(walk->lruvec, walk->max_seq, pmd + i)) continue; @@ -4309,7 +4321,7 @@ static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq, * handful of PTEs. Spreading the work out over a period of time usually * is less efficient, but it avoids bursty page faults. */ - if (!arch_has_hw_pte_young()) { + if (!(arch_has_hw_pte_young() && get_cap(LRU_GEN_MM_WALK))) { success = iterate_mm_list_nowalk(lruvec, max_seq); goto done; } @@ -5075,6 +5087,208 @@ done: } /****************************************************************************** + * state change + ******************************************************************************/ + +static bool __maybe_unused state_is_valid(struct lruvec *lruvec) +{ + struct lru_gen_struct *lrugen = &lruvec->lrugen; + + if (lrugen->enabled) { + enum lru_list lru; + + for_each_evictable_lru(lru) { + if (!list_empty(&lruvec->lists[lru])) + return false; + } + } else { + int gen, type, zone; + + for_each_gen_type_zone(gen, type, zone) { + if (!list_empty(&lrugen->lists[gen][type][zone])) + return false; + } + } + + return true; +} + +static bool fill_evictable(struct lruvec *lruvec) +{ + enum lru_list lru; + int remaining = MAX_LRU_BATCH; + + for_each_evictable_lru(lru) { + int type = is_file_lru(lru); + bool active = is_active_lru(lru); + struct list_head *head = &lruvec->lists[lru]; + + while (!list_empty(head)) { + bool success; + struct folio *folio = lru_to_folio(head); + + VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio); + VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio) != active, folio); + VM_WARN_ON_ONCE_FOLIO(folio_is_file_lru(folio) != type, folio); + VM_WARN_ON_ONCE_FOLIO(folio_lru_gen(folio) != -1, folio); + + lruvec_del_folio(lruvec, folio); + success = lru_gen_add_folio(lruvec, folio, false); + VM_WARN_ON_ONCE(!success); + + if (!--remaining) + return false; + } + } + + return true; +} + +static bool drain_evictable(struct lruvec *lruvec) +{ + int gen, type, zone; + int remaining = MAX_LRU_BATCH; + + for_each_gen_type_zone(gen, type, zone) { + struct list_head *head = &lruvec->lrugen.lists[gen][type][zone]; + + while (!list_empty(head)) { + bool success; + struct folio *folio = lru_to_folio(head); + + VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio); + VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio); + VM_WARN_ON_ONCE_FOLIO(folio_is_file_lru(folio) != type, folio); + VM_WARN_ON_ONCE_FOLIO(folio_zonenum(folio) != zone, folio); + + success = lru_gen_del_folio(lruvec, folio, false); + VM_WARN_ON_ONCE(!success); + lruvec_add_folio(lruvec, folio); + + if (!--remaining) + return false; + } + } + + return true; +} + +static void lru_gen_change_state(bool enabled) +{ + static DEFINE_MUTEX(state_mutex); + + struct mem_cgroup *memcg; + + cgroup_lock(); + cpus_read_lock(); + get_online_mems(); + mutex_lock(&state_mutex); + + if (enabled == lru_gen_enabled()) + goto unlock; + + if (enabled) + static_branch_enable_cpuslocked(&lru_gen_caps[LRU_GEN_CORE]); + else + static_branch_disable_cpuslocked(&lru_gen_caps[LRU_GEN_CORE]); + + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + int nid; + + for_each_node(nid) { + struct lruvec *lruvec = get_lruvec(memcg, nid); + + if (!lruvec) + continue; + + spin_lock_irq(&lruvec->lru_lock); + + VM_WARN_ON_ONCE(!seq_is_valid(lruvec)); + VM_WARN_ON_ONCE(!state_is_valid(lruvec)); + + lruvec->lrugen.enabled = enabled; + + while (!(enabled ? fill_evictable(lruvec) : drain_evictable(lruvec))) { + spin_unlock_irq(&lruvec->lru_lock); + cond_resched(); + spin_lock_irq(&lruvec->lru_lock); + } + + spin_unlock_irq(&lruvec->lru_lock); + } + + cond_resched(); + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL))); +unlock: + mutex_unlock(&state_mutex); + put_online_mems(); + cpus_read_unlock(); + cgroup_unlock(); +} + +/****************************************************************************** + * sysfs interface + ******************************************************************************/ + +static ssize_t show_enabled(struct kobject *kobj, struct kobj_attribute *attr, char *buf) +{ + unsigned int caps = 0; + + if (get_cap(LRU_GEN_CORE)) + caps |= BIT(LRU_GEN_CORE); + + if (arch_has_hw_pte_young() && get_cap(LRU_GEN_MM_WALK)) + caps |= BIT(LRU_GEN_MM_WALK); + + if (IS_ENABLED(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG) && get_cap(LRU_GEN_NONLEAF_YOUNG)) + caps |= BIT(LRU_GEN_NONLEAF_YOUNG); + + return snprintf(buf, PAGE_SIZE, "0x%04x\n", caps); +} + +static ssize_t store_enabled(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t len) +{ + int i; + unsigned int caps; + + if (tolower(*buf) == 'n') + caps = 0; + else if (tolower(*buf) == 'y') + caps = -1; + else if (kstrtouint(buf, 0, &caps)) + return -EINVAL; + + for (i = 0; i < NR_LRU_GEN_CAPS; i++) { + bool enabled = caps & BIT(i); + + if (i == LRU_GEN_CORE) + lru_gen_change_state(enabled); + else if (enabled) + static_branch_enable(&lru_gen_caps[i]); + else + static_branch_disable(&lru_gen_caps[i]); + } + + return len; +} + +static struct kobj_attribute lru_gen_enabled_attr = __ATTR( + enabled, 0644, show_enabled, store_enabled +); + +static struct attribute *lru_gen_attrs[] = { + &lru_gen_enabled_attr.attr, + NULL +}; + +static struct attribute_group lru_gen_attr_group = { + .name = "lru_gen", + .attrs = lru_gen_attrs, +}; + +/****************************************************************************** * initialization ******************************************************************************/ @@ -5084,6 +5298,7 @@ void lru_gen_init_lruvec(struct lruvec *lruvec) struct lru_gen_struct *lrugen = &lruvec->lrugen; lrugen->max_seq = MIN_NR_GENS + 1; + lrugen->enabled = lru_gen_enabled(); for_each_gen_type_zone(gen, type, zone) INIT_LIST_HEAD(&lrugen->lists[gen][type][zone]); @@ -5123,6 +5338,9 @@ static int __init init_lru_gen(void) BUILD_BUG_ON(MIN_NR_GENS + 1 >= MAX_NR_GENS); BUILD_BUG_ON(BIT(LRU_GEN_WIDTH) <= MAX_NR_GENS); + if (sysfs_create_group(mm_kobj, &lru_gen_attr_group)) + pr_err("lru_gen: failed to create sysfs group\n"); + return 0; }; late_initcall(init_lru_gen); |