On Fri, 30 Mar 2018 11:30:55 +0800 Wei Yang <richard.weiyang@xxxxxxxxx> wrote:
> memblock_search_pfn_nid() returns the nid and the [start|end]_pfn of the
> memory region where pfn sits in. While the calculation of start_pfn has
> potential issue when the regions base is not page aligned.
>
> For example, we assume PAGE_SHIFT is 12 and base is 0x1234. Current
> implementation would return 1 while this is not correct.
Why is this not correct? The caller might want the pfn of the page
which covers the base?
> This patch fixes this by using PFN_UP().
>
> The original commit is commit e76b63f80d93 ("memblock, numa: binary search
> node id") and merged in v3.12.
>
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> Cc: 3.12+ <stable@xxxxxxxxxxxxxxx>
Please fully describe the runtime effects of a bug when fixing that
bug. This description doesn't give enough justification for merging
the patch into mainline, let alone -stable.