mm/swap: add helper swap_offset_available()
Add helper swap_offset_available() to remove some duplicated codes. Minor
readability improvement.
[[email protected]: s/swap_offset_available/swap_offset_available_and_locked/, per Neil]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Howells <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: NeilBrown <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Oscar Salvador <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index f64b298..331aa0c 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 @@ static int scan_swap_map_slots(struct swap_info_struct *si,
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 @@ static int scan_swap_map_slots(struct swap_info_struct *si,
}
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;
