Messages in this thread Patch in this message |  | | | Date | Fri, 18 Jan 2008 16:28:42 +0900 | | From | KOSAKI Motohiro <> | | Subject | Re: [RFC][PATCH] a bit improvement of ZONE_DMA page reclaim | |
Hi Andrew
> > on X86, ZONE_DMA is very very small.
> > It is often no used at all.
>
> In that case page-reclaim is supposed to set all_unreclaimable and
> basically ignores the zone altogether until it looks like something might
> have changed.
>
> Is that code not working? (quite possible).
please insert blow debug printk and dd if=bigfile of=/dev/null.
you see "near_oom(DMA) 0 0 0" messages :)
at least, I can reproduce it on my machine.
my machine
CPU: x86_64 1.86GHz x2
memory: 6G
- kosaki
Index: b/mm/vmscan.c
===================================================================
--- a/mm/vmscan.c 2008-01-18 14:49:06.000000000 +0900
+++ b/mm/vmscan.c 2008-01-18 14:50:21.000000000 +0900
@@ -966,8 +966,14 @@ static int calc_reclaim_mapped(struct sc
int reclaim_mapped = 0;
int prev_priority;
- if (scan_global_lru(sc) && zone_is_near_oom(zone))
+ if (scan_global_lru(sc) && zone_is_near_oom(zone)) {
+ printk("near_oom(%s) %ld %ld %ld\n",
+ zone->name,
+ zone->pages_scanned,
+ zone_page_state(zone, NR_ACTIVE),
+ zone_page_state(zone, NR_INACTIVE));
return 1;
+ }
/*
* `distress' is a measure of how much trouble we're having
* reclaiming pages. 0 -> no problems. 100 -> great trouble.
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