Re: [PATCH 2/2] mm/sparsemem: Fix a bug in free_map_bootmem whenCONFIG_SPARSEMEM_VMEMMAP

From: Andrew Morton
Date: Thu Oct 03 2013 - 16:42:11 EST


On Thu, 03 Oct 2013 11:32:02 +0800 Zhang Yanfei <zhangyanfei.yes@xxxxxxxxx> wrote:

> We pass the number of pages which hold page structs of a memory
> section to function free_map_bootmem. This is right when
> !CONFIG_SPARSEMEM_VMEMMAP but wrong when CONFIG_SPARSEMEM_VMEMMAP.
> When CONFIG_SPARSEMEM_VMEMMAP, we should pass the number of pages
> of a memory section to free_map_bootmem.
>
> So the fix is removing the nr_pages parameter. When
> CONFIG_SPARSEMEM_VMEMMAP, we directly use the prefined marco
> PAGES_PER_SECTION in free_map_bootmem. When !CONFIG_SPARSEMEM_VMEMMAP,
> we calculate page numbers needed to hold the page structs for a
> memory section and use the value in free_map_bootmem.

What were the runtime user-visible effects of that bug?

Please always include this information when fixing a bug.
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