2005-12-01 10:15:17

by Wu Fengguang

[permalink] [raw]
Subject: [PATCH 12/12] mm: fix minor scan count bugs

- in isolate_lru_pages(): reports one more scan. Fix it.
- in shrink_cache(): 0 pages taken does not mean 0 pages scanned. Fix it.

Signed-off-by: Wu Fengguang <[email protected]>
---

mm/vmscan.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)

--- linux.orig/mm/vmscan.c
+++ linux/mm/vmscan.c
@@ -920,7 +920,8 @@ static int isolate_lru_pages(int nr_to_s
struct page *page;
int scan = 0;

- while (scan++ < nr_to_scan && !list_empty(src)) {
+ while (scan < nr_to_scan && !list_empty(src)) {
+ scan++;
page = lru_to_page(src);
prefetchw_prev_lru_page(page, src, flags);

@@ -967,14 +968,15 @@ static void shrink_cache(struct zone *zo
update_zone_age(zone, nr_scan);
spin_unlock_irq(&zone->lru_lock);

- if (nr_taken == 0)
- return;
-
sc->nr_scanned += nr_scan;
if (current_is_kswapd())
mod_page_state_zone(zone, pgscan_kswapd, nr_scan);
else
mod_page_state_zone(zone, pgscan_direct, nr_scan);
+
+ if (nr_taken == 0)
+ return;
+
nr_freed = shrink_list(&page_list, sc);
if (current_is_kswapd())
mod_page_state(kswapd_steal, nr_freed);

--