On Wed 21-12-16 12:43:20, Wei Yang wrote:
> On Wed, Dec 21, 2016 at 08:48:09AM +0100, Michal Hocko wrote:
> >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.
>
> Thanks~
>
> I would feel honored if you would like to add Acked-by :-)
My Nack to the original patch still holds. If you want to remove the
check then remove it rather than comment it out.
--
Michal Hocko
SUSE Labs
