Messages in this thread Patch in this message | | | Date | Tue, 11 Sep 2012 17:44:13 +0800 | From | Lai Jiangshan <> | Subject | [V4 PATCH 27/27] memory,hotplug: Don't modify the zone_start_pfn outside of zone_span_writelock() |
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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 <laijs@cn.fujitsu.com> Reported-by: Yasuaki ISIMATU <isimatu.yasuaki@jp.fujitsu.com> Tested-by: Wen Congyang <wency@cn.fujitsu.com> --- 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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