diff options
| -rw-r--r-- | mm/percpu.c | 48 |
1 files changed, 38 insertions, 10 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index 7d9bc35e8ed2..4c8a419119da 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -63,6 +63,7 @@ #include <linux/rbtree.h> #include <linux/slab.h> #include <linux/vmalloc.h> +#include <linux/workqueue.h> #include <asm/cacheflush.h> #include <asm/tlbflush.h> @@ -118,6 +119,10 @@ static DEFINE_MUTEX(pcpu_mutex); static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ static struct rb_root pcpu_addr_root = RB_ROOT; /* chunks by address */ +/* reclaim work to release fully free chunks, scheduled from free path */ +static void pcpu_reclaim(struct work_struct *work); +static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); + static int __pcpu_size_to_slot(int size) { int highbit = fls(size); /* size is in bytes */ @@ -846,13 +851,37 @@ void *__alloc_reserved_percpu(size_t size, size_t align) return pcpu_alloc(size, align, true); } -static void pcpu_kill_chunk(struct pcpu_chunk *chunk) +/** + * pcpu_reclaim - reclaim fully free chunks, workqueue function + * @work: unused + * + * Reclaim all fully free chunks except for the first one. + */ +static void pcpu_reclaim(struct work_struct *work) { - WARN_ON(chunk->immutable); - pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false); - list_del(&chunk->list); - rb_erase(&chunk->rb_node, &pcpu_addr_root); - free_pcpu_chunk(chunk); + LIST_HEAD(todo); + struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; + struct pcpu_chunk *chunk, *next; + + mutex_lock(&pcpu_mutex); + + list_for_each_entry_safe(chunk, next, head, list) { + WARN_ON(chunk->immutable); + + /* spare the first one */ + if (chunk == list_first_entry(head, struct pcpu_chunk, list)) + continue; + + rb_erase(&chunk->rb_node, &pcpu_addr_root); + list_move(&chunk->list, &todo); + } + + mutex_unlock(&pcpu_mutex); + + list_for_each_entry_safe(chunk, next, &todo, list) { + pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false); + free_pcpu_chunk(chunk); + } } /** @@ -877,14 +906,13 @@ void free_percpu(void *ptr) pcpu_free_area(chunk, off); - /* the chunk became fully free, kill one if there are other free ones */ + /* if there are more than one fully free chunks, wake up grim reaper */ if (chunk->free_size == pcpu_unit_size) { struct pcpu_chunk *pos; - list_for_each_entry(pos, - &pcpu_slot[pcpu_chunk_slot(chunk)], list) + list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) if (pos != chunk) { - pcpu_kill_chunk(pos); + schedule_work(&pcpu_reclaim_work); break; } } |