[RFC 0/2] GFP_NOFAIL cleanups

[Michal Hocko]

Hi,
Tetsuo has noticed [1] that recent changes have changed GFP_NOFAIL
semantic for costly order requests. I believe that the primary reason
why this happened is that our GFP_NOFAIL checks are too scattered
and it is really easy to forget about adding one. That's why I am
proposing patch 1 which consolidates all the nofail handling at a single
place. This should help to make this code better maintainable.

Patch 2 on top is a further attempt to make GFP_NOFAIL semantic less
surprising. As things stand currently GFP_NOFAIL overrides the oom killer
prevention code which is both subtle and not really needed. The patch 2
has more details about issues this might cause.

I would consider both patches more a cleanup than anything else. Any
feedback is highly appreciated.

[1] http://lkml.kernel.org/r/1479387004-5998-1-git-send-email-penguin-kernel@xxxxxxxxxxxxxxxxxxx