Re: [PATCH 2/2] mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask

From: Andrew Morton
Date: Thu Oct 18 2018 - 22:11:51 EST

On Wed, 26 Sep 2018 16:22:27 +0200 Michal Hocko <mhocko@xxxxxxxxxx> wrote:

> > MPOL_PREFERRED is handled by policy_node() before we call __alloc_pages_nodemask.
> > __GFP_THISNODE is applied only when we are not using
> > __GFP_DIRECT_RECLAIM which is handled in alloc_hugepage_direct_gfpmask
> > now.
> > Lastly MPOL_BIND wasn't handled explicitly but in the end the removed
> > late check would remove __GFP_THISNODE for it as well. So in the end we
> > are doing the same thing unless I miss something
> Forgot to add. One notable exception would be that the previous code
> would allow to hit
> WARN_ON_ONCE(policy->mode == MPOL_BIND && (gfp & __GFP_THISNODE));
> in policy_node if the requested node (e.g. cpu local one) was outside of
> the mbind nodemask. This is not possible now. We haven't heard about any
> such warning yet so it is unlikely that it happens though.

Perhaps a changelog addition is needed to cover the above?

I assume that David's mbind() concern has gone away.

No acks or reviewed-by's yet?