On Tue 20-12-16 16:35:40, Wei Yang wrote:
> On Mon, Dec 19, 2016 at 04:15:14PM +0100, Michal Hocko wrote:
> >On Sun 18-12-16 14:47:49, Wei Yang wrote:
> >> The base address is already guaranteed to be in the region by
> >> memblock_search().
> >
>
> Hi, Michal
>
> Nice to receive your comment.
>
> >First of all the way how the check is removed is the worst possible...
> >Apart from that it is really not clear to me why checking the base
> >is not needed. You are mentioning memblock_search but what about other
> >callers? adjust_range_page_size_mask e.g...
> >
>
> Hmm... the memblock_search() is called by memblock_is_region_memory(). Maybe I
> paste the whole function here would clarify the change.
>
> int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
> {
> int idx = memblock_search(&memblock.memory, base);
> phys_addr_t end = base + memblock_cap_size(base, &size);
>
> if (idx == -1)
> return 0;
> return memblock.memory.regions[idx].base <= base &&
> (memblock.memory.regions[idx].base +
> memblock.memory.regions[idx].size) >= end;
> }
Ohh, my bad. I thought that memblock_search is calling
memblock_is_region_memory. I didn't notice this is other way around.
Then I agree that the check for the base is not needed and can be
removed.
--
Michal Hocko
SUSE Labs
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