diff options
| -rw-r--r-- | include/linux/compaction.h | 16 | ||||
| -rw-r--r-- | include/linux/mmzone.h | 6 | ||||
| -rw-r--r-- | include/linux/vm_event_item.h | 1 | ||||
| -rw-r--r-- | include/trace/events/compaction.h | 55 | ||||
| -rw-r--r-- | mm/compaction.c | 222 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 9 | ||||
| -rw-r--r-- | mm/page_alloc.c | 3 | ||||
| -rw-r--r-- | mm/vmstat.c | 1 |
8 files changed, 311 insertions, 2 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h index 4cd4ddf64cc7..d7c8de583a23 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -52,6 +52,10 @@ extern void compaction_defer_reset(struct zone *zone, int order, bool alloc_success); extern bool compaction_restarting(struct zone *zone, int order); +extern int kcompactd_run(int nid); +extern void kcompactd_stop(int nid); +extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx); + #else static inline unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order, int alloc_flags, @@ -84,6 +88,18 @@ static inline bool compaction_deferred(struct zone *zone, int order) return true; } +static inline int kcompactd_run(int nid) +{ + return 0; +} +static inline void kcompactd_stop(int nid) +{ +} + +static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx) +{ +} + #endif /* CONFIG_COMPACTION */ #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 6de02ac378a0..bdd9a270a813 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -668,6 +668,12 @@ typedef struct pglist_data { mem_hotplug_begin/end() */ int kswapd_max_order; enum zone_type classzone_idx; +#ifdef CONFIG_COMPACTION + int kcompactd_max_order; + enum zone_type kcompactd_classzone_idx; + wait_queue_head_t kcompactd_wait; + struct task_struct *kcompactd; +#endif #ifdef CONFIG_NUMA_BALANCING /* Lock serializing the migrate rate limiting window */ spinlock_t numabalancing_migrate_lock; diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index 67c1dbd19c6d..58ecc056ee45 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -53,6 +53,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, COMPACTMIGRATE_SCANNED, COMPACTFREE_SCANNED, COMPACTISOLATED, COMPACTSTALL, COMPACTFAIL, COMPACTSUCCESS, + KCOMPACTD_WAKE, #endif #ifdef CONFIG_HUGETLB_PAGE HTLB_BUDDY_PGALLOC, HTLB_BUDDY_PGALLOC_FAIL, diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h index 111e5666e5eb..e215bf68f521 100644 --- a/include/trace/events/compaction.h +++ b/include/trace/events/compaction.h @@ -350,6 +350,61 @@ DEFINE_EVENT(mm_compaction_defer_template, mm_compaction_defer_reset, ); #endif +TRACE_EVENT(mm_compaction_kcompactd_sleep, + + TP_PROTO(int nid), + + TP_ARGS(nid), + + TP_STRUCT__entry( + __field(int, nid) + ), + + TP_fast_assign( + __entry->nid = nid; + ), + + TP_printk("nid=%d", __entry->nid) +); + +DECLARE_EVENT_CLASS(kcompactd_wake_template, + + TP_PROTO(int nid, int order, enum zone_type classzone_idx), + + TP_ARGS(nid, order, classzone_idx), + + TP_STRUCT__entry( + __field(int, nid) + __field(int, order) + __field(enum zone_type, classzone_idx) + ), + + TP_fast_assign( + __entry->nid = nid; + __entry->order = order; + __entry->classzone_idx = classzone_idx; + ), + + TP_printk("nid=%d order=%d classzone_idx=%-8s", + __entry->nid, + __entry->order, + __print_symbolic(__entry->classzone_idx, ZONE_TYPE)) +); + +DEFINE_EVENT(kcompactd_wake_template, mm_compaction_wakeup_kcompactd, + + TP_PROTO(int nid, int order, enum zone_type classzone_idx), + + TP_ARGS(nid, order, classzone_idx) +); + +DEFINE_EVENT(kcompactd_wake_template, mm_compaction_kcompactd_wake, + + TP_PROTO(int nid, int order, enum zone_type classzone_idx), + + TP_ARGS(nid, order, classzone_idx) +); + #endif /* _TRACE_COMPACTION_H */ /* This part must be outside protection */ diff --git a/mm/compaction.c b/mm/compaction.c index 93f71d968098..5b2bfbaa821a 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -7,6 +7,7 @@ * * Copyright IBM Corp. 2007-2010 Mel Gorman <mel@csn.ul.ie> */ +#include <linux/cpu.h> #include <linux/swap.h> #include <linux/migrate.h> #include <linux/compaction.h> @@ -17,6 +18,8 @@ #include <linux/balloon_compaction.h> #include <linux/page-isolation.h> #include <linux/kasan.h> +#include <linux/kthread.h> +#include <linux/freezer.h> #include "internal.h" #ifdef CONFIG_COMPACTION @@ -1736,4 +1739,223 @@ void compaction_unregister_node(struct node *node) } #endif /* CONFIG_SYSFS && CONFIG_NUMA */ +static inline bool kcompactd_work_requested(pg_data_t *pgdat) +{ + return pgdat->kcompactd_max_order > 0; +} + +static bool kcompactd_node_suitable(pg_data_t *pgdat) +{ + int zoneid; + struct zone *zone; + enum zone_type classzone_idx = pgdat->kcompactd_classzone_idx; + + for (zoneid = 0; zoneid < classzone_idx; zoneid++) { + zone = &pgdat->node_zones[zoneid]; + + if (!populated_zone(zone)) + continue; + + if (compaction_suitable(zone, pgdat->kcompactd_max_order, 0, + classzone_idx) == COMPACT_CONTINUE) + return true; + } + + return false; +} + +static void kcompactd_do_work(pg_data_t *pgdat) +{ + /* + * With no special task, compact all zones so that a page of requested + * order is allocatable. + */ + int zoneid; + struct zone *zone; + struct compact_control cc = { + .order = pgdat->kcompactd_max_order, + .classzone_idx = pgdat->kcompactd_classzone_idx, + .mode = MIGRATE_SYNC_LIGHT, + .ignore_skip_hint = true, + + }; + bool success = false; + + trace_mm_compaction_kcompactd_wake(pgdat->node_id, cc.order, + cc.classzone_idx); + count_vm_event(KCOMPACTD_WAKE); + + for (zoneid = 0; zoneid < cc.classzone_idx; zoneid++) { + int status; + + zone = &pgdat->node_zones[zoneid]; + if (!populated_zone(zone)) + continue; + + if (compaction_deferred(zone, cc.order)) + continue; + + if (compaction_suitable(zone, cc.order, 0, zoneid) != + COMPACT_CONTINUE) + continue; + + cc.nr_freepages = 0; + cc.nr_migratepages = 0; + cc.zone = zone; + INIT_LIST_HEAD(&cc.freepages); + INIT_LIST_HEAD(&cc.migratepages); + + status = compact_zone(zone, &cc); + + if (zone_watermark_ok(zone, cc.order, low_wmark_pages(zone), + cc.classzone_idx, 0)) { + success = true; + compaction_defer_reset(zone, cc.order, false); + } else if (status == COMPACT_COMPLETE) { + /* + * We use sync migration mode here, so we defer like + * sync direct compaction does. + */ + defer_compaction(zone, cc.order); + } + + VM_BUG_ON(!list_empty(&cc.freepages)); + VM_BUG_ON(!list_empty(&cc.migratepages)); + } + + /* + * Regardless of success, we are done until woken up next. But remember + * the requested order/classzone_idx in case it was higher/tighter than + * our current ones + */ + if (pgdat->kcompactd_max_order <= cc.order) + pgdat->kcompactd_max_order = 0; + if (pgdat->kcompactd_classzone_idx >= cc.classzone_idx) + pgdat->kcompactd_classzone_idx = pgdat->nr_zones - 1; +} + +void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx) +{ + if (!order) + return; + + if (pgdat->kcompactd_max_order < order) + pgdat->kcompactd_max_order = order; + + if (pgdat->kcompactd_classzone_idx > classzone_idx) + pgdat->kcompactd_classzone_idx = classzone_idx; + + if (!waitqueue_active(&pgdat->kcompactd_wait)) + return; + + if (!kcompactd_node_suitable(pgdat)) + return; + + trace_mm_compaction_wakeup_kcompactd(pgdat->node_id, order, + classzone_idx); + wake_up_interruptible(&pgdat->kcompactd_wait); +} + +/* + * The background compaction daemon, started as a kernel thread + * from the init process. + */ +static int kcompactd(void *p) +{ + pg_data_t *pgdat = (pg_data_t*)p; + struct task_struct *tsk = current; + + const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); + + if (!cpumask_empty(cpumask)) + set_cpus_allowed_ptr(tsk, cpumask); + + set_freezable(); + + pgdat->kcompactd_max_order = 0; + pgdat->kcompactd_classzone_idx = pgdat->nr_zones - 1; + + while (!kthread_should_stop()) { + trace_mm_compaction_kcompactd_sleep(pgdat->node_id); + wait_event_freezable(pgdat->kcompactd_wait, + kcompactd_work_requested(pgdat)); + + kcompactd_do_work(pgdat); + } + + return 0; +} + +/* + * This kcompactd start function will be called by init and node-hot-add. + * On node-hot-add, kcompactd will moved to proper cpus if cpus are hot-added. + */ +int kcompactd_run(int nid) +{ + pg_data_t *pgdat = NODE_DATA(nid); + int ret = 0; + + if (pgdat->kcompactd) + return 0; + + pgdat->kcompactd = kthread_run(kcompactd, pgdat, "kcompactd%d", nid); + if (IS_ERR(pgdat->kcompactd)) { + pr_err("Failed to start kcompactd on node %d\n", nid); + ret = PTR_ERR(pgdat->kcompactd); + pgdat->kcompactd = NULL; + } + return ret; +} + +/* + * Called by memory hotplug when all memory in a node is offlined. Caller must + * hold mem_hotplug_begin/end(). + */ +void kcompactd_stop(int nid) +{ + struct task_struct *kcompactd = NODE_DATA(nid)->kcompactd; + + if (kcompactd) { + kthread_stop(kcompactd); + NODE_DATA(nid)->kcompactd = NULL; + } +} + +/* + * It's optimal to keep kcompactd on the same CPUs as their memory, but + * not required for correctness. So if the last cpu in a node goes + * away, we get changed to run anywhere: as the first one comes back, + * restore their cpu bindings. + */ +static int cpu_callback(struct notifier_block *nfb, unsigned long action, + void *hcpu) +{ + int nid; + + if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) { + for_each_node_state(nid, N_MEMORY) { + pg_data_t *pgdat = NODE_DATA(nid); + const struct cpumask *mask; + + mask = cpumask_of_node(pgdat->node_id); + + if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids) + /* One of our CPUs online: restore mask */ + set_cpus_allowed_ptr(pgdat->kcompactd, mask); + } + } + return NOTIFY_OK; +} + +static int __init kcompactd_init(void) +{ + int nid; + + for_each_node_state(nid, N_MEMORY) + kcompactd_run(nid); + hotcpu_notifier(cpu_callback, 0); + return 0; +} +subsys_initcall(kcompactd_init) + #endif /* CONFIG_COMPACTION */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 24ea06393816..d9bcb26fc4df 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -33,6 +33,7 @@ #include <linux/hugetlb.h> #include <linux/memblock.h> #include <linux/bootmem.h> +#include <linux/compaction.h> #include <asm/tlbflush.h> @@ -1105,8 +1106,10 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ init_per_zone_wmark_min(); - if (onlined_pages) + if (onlined_pages) { kswapd_run(zone_to_nid(zone)); + kcompactd_run(nid); + } vm_total_pages = nr_free_pagecache_pages(); @@ -1880,8 +1883,10 @@ repeat: zone_pcp_update(zone); node_states_clear_node(node, &arg); - if (arg.status_change_nid >= 0) + if (arg.status_change_nid >= 0) { kswapd_stop(node); + kcompactd_stop(node); + } vm_total_pages = nr_free_pagecache_pages(); writeback_set_ratelimit(); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b1fc19ebb8a2..25a75da53c27 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5405,6 +5405,9 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat) #endif init_waitqueue_head(&pgdat->kswapd_wait); init_waitqueue_head(&pgdat->pfmemalloc_wait); +#ifdef CONFIG_COMPACTION + init_waitqueue_head(&pgdat->kcompactd_wait); +#endif pgdat_page_ext_init(pgdat); for (j = 0; j < MAX_NR_ZONES; j++) { diff --git a/mm/vmstat.c b/mm/vmstat.c index 69ce64f7b8d7..f80066248c94 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -826,6 +826,7 @@ const char * const vmstat_text[] = { "compact_stall", "compact_fail", "compact_success", + "compact_daemon_wake", #endif #ifdef CONFIG_HUGETLB_PAGE |