From 4b9ae8426cb4a9160ae41bc968391f499feece7e Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Thu, 19 May 2022 14:08:52 -0700 Subject: mm/swap: add helper swap_offset_available() Add helper swap_offset_available() to remove some duplicated codes. Minor readability improvement. [akpm@linux-foundation.org: s/swap_offset_available/swap_offset_available_and_locked/, per Neil] Link: https://lkml.kernel.org/r/20220509131416.17553-12-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Cc: Alistair Popple Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox Cc: Naoya Horiguchi Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Oscar Salvador Signed-off-by: Andrew Morton --- mm/swapfile.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index f64b298f1034..331aa0cc5b9e 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -775,6 +775,22 @@ static void set_cluster_next(struct swap_info_struct *si, unsigned long next) this_cpu_write(*si->cluster_next_cpu, next); } +static bool swap_offset_available_and_locked(struct swap_info_struct *si, + unsigned long offset) +{ + if (data_race(!si->swap_map[offset])) { + spin_lock(&si->lock); + return true; + } + + if (vm_swap_full() && READ_ONCE(si->swap_map[offset]) == SWAP_HAS_CACHE) { + spin_lock(&si->lock); + return true; + } + + return false; +} + static int scan_swap_map_slots(struct swap_info_struct *si, unsigned char usage, int nr, swp_entry_t slots[]) @@ -952,15 +968,8 @@ done: scan: spin_unlock(&si->lock); while (++offset <= READ_ONCE(si->highest_bit)) { - if (data_race(!si->swap_map[offset])) { - spin_lock(&si->lock); + if (swap_offset_available_and_locked(si, offset)) goto checks; - } - if (vm_swap_full() && - READ_ONCE(si->swap_map[offset]) == SWAP_HAS_CACHE) { - spin_lock(&si->lock); - goto checks; - } if (unlikely(--latency_ration < 0)) { cond_resched(); latency_ration = LATENCY_LIMIT; @@ -969,15 +978,8 @@ scan: } offset = si->lowest_bit; while (offset < scan_base) { - if (data_race(!si->swap_map[offset])) { - spin_lock(&si->lock); + if (swap_offset_available_and_locked(si, offset)) goto checks; - } - if (vm_swap_full() && - READ_ONCE(si->swap_map[offset]) == SWAP_HAS_CACHE) { - spin_lock(&si->lock); - goto checks; - } if (unlikely(--latency_ration < 0)) { cond_resched(); latency_ration = LATENCY_LIMIT; -- cgit v1.2.3