Messages in this thread Patch in this message | | | Date | Thu, 24 Jan 2008 13:24:48 +0900 | From | KOSAKI Motohiro <> | Subject | [RFC][PATCH 7/8] mem_notify v5: ignore very small zone for prevent incorrect low mem notify. |
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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);
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