On Wed 21-12-16 13:13:32, Wei Yang wrote: > On Wed, Dec 21, 2016 at 08:51:16AM +0100, Michal Hocko wrote: > >On Tue 20-12-16 16:48:23, Wei Yang wrote: > >> On Mon, Dec 19, 2016 at 04:21:57PM +0100, Michal Hocko wrote: > >> >On Sun 18-12-16 14:47:50, Wei Yang wrote: > >> >> memblock_reserve() may fail in case there is not enough regions. > >> > > >> >Have you seen this happenning in the real setups or this is a by-review > >> >driven change? > >> > >> This is a by-review driven change. > >> > >> >[...] > >> >> again: > >> >> alloc = memblock_find_in_range_node(size, align, min_addr, max_addr, > >> >> nid, flags); > >> >> - if (alloc) > >> >> + if (alloc && !memblock_reserve(alloc, size)) > >> >> goto done; > > > >So how exactly does the reserve fail when memblock_find_in_range_node > >found a suitable range for the given size? > > > > Even memblock_find_in_range_node() gets a suitable range, memblock_reserve() > still could fail. And the case just happens when memblock can't resize. > memblock_reserve() reserve a range by adding a range to memblock.reserved. In > case the memblock.reserved is full and can't resize, this fails. Sorry for being dense but what does it mean that the reserved will get full? Also how probable is such a situation? Is it even real? In other words does this fix a real or only a theoretical problem? Anyway this all should be part of the changelog. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>