On Tue, 10 May 2022 10:03:19 +0800 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote:
> On 2022/5/10 8:45, NeilBrown wrote:
> > On Mon, 09 May 2022, Miaohe Lin wrote:
> >> Add helper swap_offset_available() to remove some duplicated codes.
> >> Minor readability improvement.
> >
> > I don't think that putting the spin_lock() inside the inline helper is
> > good for readability.
> > If the function was called
> > swap_offset_available_and_locked()
>
> Yes, swap_offset_available_and_locked should be more suitable as we do the spin_lock
> inside it. Will do this in next version.
>
--- a/mm/swapfile.c~mm-swap-add-helper-swap_offset_available-fix
+++ a/mm/swapfile.c
@@ -775,7 +775,8 @@ static void set_cluster_next(struct swap
this_cpu_write(*si->cluster_next_cpu, next);
}
-static inline bool swap_offset_available(struct swap_info_struct *si, unsigned long offset)
+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);
@@ -967,7 +968,7 @@ done:
scan:
spin_unlock(&si->lock);
while (++offset <= READ_ONCE(si->highest_bit)) {
- if (swap_offset_available(si, offset))
+ if (swap_offset_available_and_locked(si, offset))
goto checks;
if (unlikely(--latency_ration < 0)) {
cond_resched();
@@ -977,7 +978,7 @@ scan:
}
offset = si->lowest_bit;
while (offset < scan_base) {
- if (swap_offset_available(si, offset))
+ if (swap_offset_available_and_locked(si, offset))
goto checks;
if (unlikely(--latency_ration < 0)) {
cond_resched();
_
