On Wed 22-08-18 11:52:50, Andrea Arcangeli wrote:

On Wed, Aug 22, 2018 at 11:02:14AM +0200, Michal Hocko wrote:

[...]

quoted

I still have to digest the __GFP_THISNODE thing but I _think_ that the
alloc_pages_vma code is just trying to be overly clever and
__GFP_THISNODE is not a good fit for it. 

My option 2 did just that, it removed __GFP_THISNODE but only for
MADV_HUGEPAGE and in general whenever reclaim was activated by
__GFP_DIRECT_RECLAIM. That is also signal that the user really wants
THP so then it's less bad to prefer THP over NUMA locality.

For the default which is tuned for short lived allocation, preferring
local memory is most certainly better win for short lived allocation
where THP can't help much, this is why I didn't remove __GFP_THISNODE
from the default defrag policy.

Yes I agree.
-- 
Michal Hocko
SUSE Labs