Consider of performance and simplicity, this patch remove swap_lock
to simplify the si_swapinfo().
Because the system info we obtain through /proc or /sys interface is
just a snapshot, we don't need a very precise freeswap and totalswap count.
Some monitor tool will get these count at per-second period, so it is good
to performance.
Signed-off-by: Weijie Yang <weijie.yang@xxxxxxxxxxx>
---
mm/swapfile.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 3023172..7332c3d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2637,19 +2637,8 @@ out:
void si_swapinfo(struct sysinfo *val)
{
- unsigned int type;
- unsigned long nr_to_be_unused = 0;
-
- spin_lock(&swap_lock);
- for (type = 0; type < nr_swapfiles; type++) {
- struct swap_info_struct *si = swap_info[type];
-
- if ((si->flags & SWP_USED) && !(si->flags & SWP_WRITEOK))
- nr_to_be_unused += si->inuse_pages;
- }
- val->freeswap = atomic_long_read(&nr_swap_pages) + nr_to_be_unused;
- val->totalswap = total_swap_pages + nr_to_be_unused;
- spin_unlock(&swap_lock);
+ val->freeswap = atomic_long_read(&nr_swap_pages);
+ val->totalswap = total_swap_pages;
}
/*
--
1.7.10.4
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