[PATCH v3 03/10] mm: frontswap: split out __frontswap_curr_pages

From: Sasha Levin
Date: Sun Jun 10 2012 - 06:52:02 EST


Code was duplicated in two functions, clean it up.

Also, assert that the deduplicated code runs under the swap spinlock.

Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
mm/frontswap.c | 28 +++++++++++++++++-----------
1 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/mm/frontswap.c b/mm/frontswap.c
index 7ec53d5..5faf840 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -216,6 +216,20 @@ void __frontswap_invalidate_area(unsigned type)
}
EXPORT_SYMBOL(__frontswap_invalidate_area);

+static unsigned long __frontswap_curr_pages(void)
+{
+ int type;
+ unsigned long totalpages = 0;
+ struct swap_info_struct *si = NULL;
+
+ assert_spin_locked(&swap_lock);
+ for (type = swap_list.head; type >= 0; type = si->next) {
+ si = swap_info[type];
+ totalpages += atomic_read(&si->frontswap_pages);
+ }
+ return totalpages;
+}
+
/*
* Frontswap, like a true swap device, may unnecessarily retain pages
* under certain circumstances; "shrink" frontswap is essentially a
@@ -240,11 +254,7 @@ void frontswap_shrink(unsigned long target_pages)
*/
spin_lock(&swap_lock);
locked = true;
- total_pages = 0;
- for (type = swap_list.head; type >= 0; type = si->next) {
- si = swap_info[type];
- total_pages += atomic_read(&si->frontswap_pages);
- }
+ total_pages = __frontswap_curr_pages();
if (total_pages <= target_pages)
goto out;
total_pages_to_unuse = total_pages - target_pages;
@@ -282,16 +292,12 @@ EXPORT_SYMBOL(frontswap_shrink);
*/
unsigned long frontswap_curr_pages(void)
{
- int type;
unsigned long totalpages = 0;
- struct swap_info_struct *si = NULL;

spin_lock(&swap_lock);
- for (type = swap_list.head; type >= 0; type = si->next) {
- si = swap_info[type];
- totalpages += atomic_read(&si->frontswap_pages);
- }
+ totalpages = __frontswap_curr_pages();
spin_unlock(&swap_lock);
+
return totalpages;
}
EXPORT_SYMBOL(frontswap_curr_pages);
--
1.7.8.6

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