[PATCH] shrink_all_memory(): fix lru_pages handling

At the end of shrink_all_memory() we forget to recalculate lru_pages: it can
be zero.

Fix that up, and add a helper function for this operation too.

Also, recalculate lru_pages each time around the inner loop to get the
balancing correct.

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andrew Morton 2007-01-05 16:37:05 -08:00 committed by Linus Torvalds
parent d63b70902b
commit 76395d3761

View file

@ -1406,6 +1406,16 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio,
return ret;
}
static unsigned long count_lru_pages(void)
{
struct zone *zone;
unsigned long ret = 0;
for_each_zone(zone)
ret += zone->nr_active + zone->nr_inactive;
return ret;
}
/*
* Try to free `nr_pages' of memory, system-wide, and return the number of
* freed pages.
@ -1420,7 +1430,6 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
unsigned long ret = 0;
int pass;
struct reclaim_state reclaim_state;
struct zone *zone;
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
.may_swap = 0,
@ -1431,10 +1440,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
current->reclaim_state = &reclaim_state;
lru_pages = 0;
for_each_zone(zone)
lru_pages += zone->nr_active + zone->nr_inactive;
lru_pages = count_lru_pages();
nr_slab = global_page_state(NR_SLAB_RECLAIMABLE);
/* If slab caches are huge, it's better to hit them first */
while (nr_slab >= lru_pages) {
@ -1461,13 +1467,6 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
for (pass = 0; pass < 5; pass++) {
int prio;
/* Needed for shrinking slab caches later on */
if (!lru_pages)
for_each_zone(zone) {
lru_pages += zone->nr_active;
lru_pages += zone->nr_inactive;
}
/* Force reclaiming mapped pages in the passes #3 and #4 */
if (pass > 2) {
sc.may_swap = 1;
@ -1483,7 +1482,8 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
goto out;
reclaim_state.reclaimed_slab = 0;
shrink_slab(sc.nr_scanned, sc.gfp_mask, lru_pages);
shrink_slab(sc.nr_scanned, sc.gfp_mask,
count_lru_pages());
ret += reclaim_state.reclaimed_slab;
if (ret >= nr_pages)
goto out;
@ -1491,20 +1491,19 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
if (sc.nr_scanned && prio < DEF_PRIORITY - 2)
congestion_wait(WRITE, HZ / 10);
}
lru_pages = 0;
}
/*
* If ret = 0, we could not shrink LRUs, but there may be something
* in slab caches
*/
if (!ret)
if (!ret) {
do {
reclaim_state.reclaimed_slab = 0;
shrink_slab(nr_pages, sc.gfp_mask, lru_pages);
shrink_slab(nr_pages, sc.gfp_mask, count_lru_pages());
ret += reclaim_state.reclaimed_slab;
} while (ret < nr_pages && reclaim_state.reclaimed_slab > 0);
}
out:
current->reclaim_state = NULL;