- If max_scan evaluates to zero due to a very small inactive list and high
`priority' numbers, we don't want to thrlttle yet.
- In balance_pgdat(), we may end up not scanning any pages because all
zones happened to be above pages_high. Avoid throttling in this case too.
---
mm/vmscan.c | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)
diff -puN mm/vmscan.c~vmscan-dont-throttle-if-zero-max_scan mm/vmscan.c
--- 25/mm/vmscan.c~vmscan-dont-throttle-if-zero-max_scan 2004-02-28 23:38:15.000000000 -0800
+++ 25-akpm/mm/vmscan.c 2004-02-28 23:38:15.000000000 -0800
@@ -872,7 +872,8 @@ int try_to_free_pages(struct zone **zone
wakeup_bdflush(total_scanned);
/* Take a nap, wait for some writeback to complete */
- blk_congestion_wait(WRITE, HZ/10);
+ if (total_scanned)
+ blk_congestion_wait(WRITE, HZ/10);
}
if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY))
out_of_memory();
@@ -917,6 +918,7 @@ static int balance_pgdat(pg_data_t *pgda
for (priority = DEF_PRIORITY; priority; priority--) {
int all_zones_ok = 1;
+ int pages_scanned = 0;
for (i = 0; i < pgdat->nr_zones; i++) {
struct zone *zone = pgdat->node_zones + i;
@@ -935,6 +937,7 @@ static int balance_pgdat(pg_data_t *pgda
max_scan = zone->nr_inactive >> priority;
reclaimed = shrink_zone(zone, max_scan, GFP_KERNEL,
&total_scanned, ps);
+ total_scanned += pages_scanned;
reclaim_state->reclaimed_slab = 0;
shrink_slab(total_scanned, GFP_KERNEL);
reclaimed += reclaim_state->reclaimed_slab;
@@ -952,7 +955,8 @@ static int balance_pgdat(pg_data_t *pgda
* OK, kswapd is getting into trouble. Take a nap, then take
* another pass across the zones.
*/
- blk_congestion_wait(WRITE, HZ/10);
+ if (pages_scanned)
+ blk_congestion_wait(WRITE, HZ/10);
}
for (i = 0; i < pgdat->nr_zones; i++) {
_