Messages in this thread |  | | | Date | Fri, 9 May 2008 15:39:10 +0900 | | From | KAMEZAWA Hiroyuki <> | | Subject | Re: [PATCH] memory_hotplug: always initialize pageblock bitmap. |
On Fri, 9 May 2008 08:06:09 +0200
Heiko Carstens <heiko.carstens@de.ibm.com> wrote:
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> Trying to online a new memory section that was added via memory hotplug
> sometimes results in crashes when the new pages are added via
> __free_page. Reason for that is that the pageblock bitmap isn't
> initialized and hence contains random stuff.
Hmm, curious. In my understanding, memmap_init_zone() initializes it.
__add_pages()
-> __add_section()
-> sparse-add_one_section() // allocate usemap
-> __add_zone()
-> memmap_init_zone() // reset pageblock's bitmap
Can't memmap_init_zone() does proper initialization ?
........................
Ah, ok. I see. grow_zone_span() is not called at __add_zone(), then,
memmap_init_zone() doesn't initialize usemap because memmap is not in zone's
range.
Recently, I added a check "zone's start_pfn < pfn < zone's end"
to memmap_init_zone()'s usemap initialization for !SPARSEMEM case bug FIX.
(and I think the fix itself is sane.)
How about calling grow_pgdat_span()/grow_zone_span() from __add_zone() ?
Thanks,
-Kame
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