[PATCH v4 8/9] mm/swap: Enable swap slots cache usage

Tim Chen
2016-12-09T21:10:42Z

Initialize swap slots cache and enable it on swap on.
Drain all swap slots on swap off.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
---
mm/swapfile.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 3a6cad1..2440cec 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2184,6 +2184,8 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
spin_unlock(&p->lock);
spin_unlock(&swap_lock);

+ disable_swap_slots_cache_lock();
+
set_current_oom_origin();
err = try_to_unuse(p->type, false, 0); /* force unuse all pages */
clear_current_oom_origin();
@@ -2191,9 +2193,12 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
if (err) {
/* re-insert swap space back into swap_list */
reinsert_swap_info(p);
+ reenable_swap_slots_cache_unlock();
goto out_dput;
}

+ reenable_swap_slots_cache_unlock();
+
flush_work(&p->discard_work);

destroy_swap_extents(p);
@@ -2871,6 +2876,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
putname(name);
if (inode && S_ISREG(inode->i_mode))
inode_unlock(inode);
+ if (!error)
+ enable_swap_slots_cache();
return error;
}

--
2.5.5