Hi Lai,
2012/09/11 18:44, Lai Jiangshan wrote:
On 09/11/2012 08:40 AM, Yasuaki Ishimatsu wrote:
Hi Lai,
Using memory_online to hot-added node's memory, the following kernel messages
were shown. Is this a known issue?
Fixed.
Subject: Don't modify the zone_start_pfn outside of zone_span_writelock()
Original __add_zone() and new online_movable/online_kernel
maybe call sleep-able init_currently_empty_zone() to init wait_table,
but this function also modifies the zone_start_pfn without lock.
so we move this code out, and ensure the modification of zone_start_pfn is done
with zone_span_writelock() held or booting.
Since zone_start_pfn is not modified by init_currently_empty_zone()
grow_zone_span() needs to be updated to be aware of empty zone.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
Reported-by: Yasuaki ISIMATU <isimatu.yasu...@jp.fujitsu.com>
Tested-by: Wen Congyang <we...@cn.fujitsu.com>
Applying the patch, the kernel messages disappeared. Thanks.
But I have a question. Using online_movable, the following messages are shown.
[ 608.314608] Built 3 zonelists in Node order, mobility grouping on. Total
pages: 7844412
[ 608.411478] Policy zone: Normal
I think memory is allocated to ZONE_MOVABLE by using online_movable.
So why is "Policy zone: Normal" shown? It should be "Policy zone: Movable"
Thanks,
Yasuaki Ishimatsu
---
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 3ad25f9..c26a4ea 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -201,7 +201,7 @@ static void grow_zone_span(struct zone *zone, unsigned long
start_pfn,
zone_span_writelock(zone);
old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
- if (start_pfn < zone->zone_start_pfn)
+ if (!zone->zone_start_pfn || start_pfn < zone->zone_start_pfn)
zone->zone_start_pfn = start_pfn;
zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 009ac28..637b4f8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3991,8 +3991,6 @@ int __meminit init_currently_empty_zone(struct zone *zone,
return ret;
pgdat->nr_zones = zone_idx(zone) + 1;
- zone->zone_start_pfn = zone_start_pfn;
-
mminit_dprintk(MMINIT_TRACE, "memmap_init",
"Initialising map node %d zone %lu pfns %lu -> %lu\n",
pgdat->node_id,
@@ -4459,6 +4457,7 @@ static void __paginginit free_area_init_core(struct
pglist_data *pgdat,
ret = init_currently_empty_zone(zone, zone_start_pfn,
size, MEMMAP_EARLY);
BUG_ON(ret);
+ zone->zone_start_pfn = zone_start_pfn;
memmap_init(size, nid, j, zone_start_pfn);
zone_start_pfn += size;
}
--
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