Re: [RFC][-mm][PATCH 3/6] oom-killer: count lowmem rss

From: KAMEZAWA Hiroyuki
Date: Mon Nov 02 2009 - 18:11:40 EST

Christoph Lameter wrote:
> I dont think this patch will work in !NUMA but its useful there too. Can
> you make this work in general?
for NUMA
+static inline int is_lowmem_page(struct page *page)
+ if (unlikely(page_zonenum(page) < policy_zone))
+ return 1;
+ return 0;

is used. Doesn't this work well ?
This check means
It enough memory:
On my ia64 box ZONE_DMA(<4G), x86-64 box(GFP_DMA32) is caught
If small memory (typically < 4G)
ia64 box no lowmem, x86-64 box GPF_DMA is caught
If all zones are policy zone (ppc)
no lowmem zone.

Because "amount of memory" changes the situation "which is lowmem?",
I used policy zone. If this usage is not appropriate, I'll add some new.

BTW, is it better to export this value from somewhere ?


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at