diff --git a/include/linux/swap.h b/include/linux/swap.h index ca533b478c212d..f3e0ac20c2e8c9 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -335,6 +335,7 @@ struct swap_info_struct { * list. */ struct work_struct discard_work; /* discard worker */ + struct work_struct reclaim_work; /* reclaim worker */ struct list_head discard_clusters; /* discard clusters list */ struct plist_node avail_lists[]; /* * entries in swap_avail_heads, one diff --git a/mm/swapfile.c b/mm/swapfile.c index b0915f3fab315f..46bd4b1a3c0714 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -731,15 +731,16 @@ static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, unsigne return offset; } -static void swap_reclaim_full_clusters(struct swap_info_struct *si) +/* Return true if reclaimed a whole cluster */ +static void swap_reclaim_full_clusters(struct swap_info_struct *si, bool force) { long to_scan = 1; unsigned long offset, end; struct swap_cluster_info *ci; unsigned char *map = si->swap_map; - int nr_reclaim, total_reclaimed = 0; + int nr_reclaim; - if (atomic_long_read(&nr_swap_pages) <= SWAPFILE_CLUSTER) + if (force) to_scan = si->inuse_pages / SWAPFILE_CLUSTER; while (!list_empty(&si->full_clusters)) { @@ -749,28 +750,36 @@ static void swap_reclaim_full_clusters(struct swap_info_struct *si) end = min(si->max, offset + SWAPFILE_CLUSTER); to_scan--; + spin_unlock(&si->lock); while (offset < end) { if (READ_ONCE(map[offset]) == SWAP_HAS_CACHE) { - spin_unlock(&si->lock); nr_reclaim = __try_to_reclaim_swap(si, offset, TTRS_ANYWAY | TTRS_DIRECT); - spin_lock(&si->lock); - if (nr_reclaim > 0) { - offset += nr_reclaim; - total_reclaimed += nr_reclaim; - continue; - } else if (nr_reclaim < 0) { - offset += -nr_reclaim; + if (nr_reclaim) { + offset += abs(nr_reclaim); continue; } } offset++; } - if (to_scan <= 0 || total_reclaimed) + spin_lock(&si->lock); + + if (to_scan <= 0) break; } } +static void swap_reclaim_work(struct work_struct *work) +{ + struct swap_info_struct *si; + + si = container_of(work, struct swap_info_struct, reclaim_work); + + spin_lock(&si->lock); + swap_reclaim_full_clusters(si, true); + spin_unlock(&si->lock); +} + /* * Try to get swap entries with specified order from current cpu's swap entry * pool (a cluster). This might involve allocating a new cluster for current CPU @@ -800,6 +809,10 @@ static unsigned long cluster_alloc_swap_entry(struct swap_info_struct *si, int o goto done; } + /* Try reclaim from full clusters if free clusters list is drained */ + if (vm_swap_full()) + swap_reclaim_full_clusters(si, false); + if (order < PMD_ORDER) { unsigned int frags = 0; @@ -881,13 +894,6 @@ static unsigned long cluster_alloc_swap_entry(struct swap_info_struct *si, int o } done: - /* Try reclaim from full clusters if device is nearfull */ - if (vm_swap_full() && (!found || (si->pages - si->inuse_pages) < SWAPFILE_CLUSTER)) { - swap_reclaim_full_clusters(si); - if (!found && !order && si->pages != si->inuse_pages) - goto new_cluster; - } - cluster->next[order] = offset; return found; } @@ -922,6 +928,9 @@ static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset, si->lowest_bit = si->max; si->highest_bit = 0; del_from_avail_list(si); + + if (vm_swap_full()) + schedule_work(&si->reclaim_work); } } @@ -2816,6 +2825,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) wait_for_completion(&p->comp); flush_work(&p->discard_work); + flush_work(&p->reclaim_work); destroy_swap_extents(p); if (p->flags & SWP_CONTINUED) @@ -3376,6 +3386,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) return PTR_ERR(si); INIT_WORK(&si->discard_work, swap_discard_work); + INIT_WORK(&si->reclaim_work, swap_reclaim_work); name = getname(specialfile); if (IS_ERR(name)) {