Cc: <kosaki.motohiro@...>, Marcelo Tosatti <marcelo@...>, Daniel Spang <daniel.spang@...>, Rik van Riel <riel@...>, Andrew Morton <akpm@...>, Alan Cox <alan@...>, <linux-fsdevel@...>, Pavel Machek <pavel@...>, Al Boldi <a1426z@...>, Jon Masters <jonathan@...>, Zan Lynx <zlynx@...>
on X86, ZONE_DMA is very very small.
it cause undesirable low mem notification.
It should ignored.
but on other some architecture, ZONE_DMA have 4GB.
4GB is large as it is not possible to ignored.
therefore, ignore or not is decided by zone size.
ChangeLog:
v5: new
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
---
include/linux/mem_notify.h | 3 +++
mm/page_alloc.c | 6 +++++-
2 files changed, 8 insertions(+), 1 deletion(-)
Index: b/include/linux/mem_notify.h
===================================================================
--- a/include/linux/mem_notify.h 2008-01-23 22:06:04.000000000 +0900
+++ b/include/linux/mem_notify.h 2008-01-23 22:08:02.000000000 +0900
@@ -22,6 +22,9 @@ static inline void memory_pressure_notif
unsigned long target;
unsigned long pages_high, pages_free, pages_reserve;
+ if (unlikely(zone->mem_notify_status == -1))
+ return;
+
if (pressure) {
target = atomic_long_read(&last_mem_notify) + MEM_NOTIFY_FREQ;
if (likely(time_before(jiffies, target)))
Index: b/mm/page_alloc.c
===================================================================
--- a/mm/page_alloc.c 2008-01-23 22:07:57.000000000 +0900
+++ b/mm/page_alloc.c 2008-01-23 22:08:02.000000000 +0900
@@ -3470,7 +3470,11 @@ static void __meminit free_area_init_cor
zone->zone_pgdat = pgdat;
zone->prev_priority = DEF_PRIORITY;
- zone->mem_notify_status = 0;
+
+ if (zone->present_pages < (pgdat->node_present_pages / 10))
+ zone->mem_notify_status = -1;
+ else
+ zone->mem_notify_status = 0;
zone_pcp_init(zone);
INIT_LIST_HEAD(&zone->active_list);
--
