[PATCH 0/3] oom reaper follow ups v1

[Michal Hocko]

Hi,
the following three patches should help to reduce the corner case space
for oom livelocks even further.

Patch1 is something that we should have probably done quite some time
ago. GFP_NOFS requests never got access to memory reserves even when a
task was killed. As this has some side effect to oom notifiers I have
CCed curret users of this interface to hear from them. The patch contains
more detailed information.

Patch2 builds on top and allows tasks which skip the regular OOM killer
(e.g. those with fatal_signal_pending) to queue them for oom reaper if
there is not a risk that somebody sharing the mm with them could see
this from the userspace. I have cced Oleg on this patch because I am not
entirely sure I am doing it properly.

Finally the last patch relaxes TIF_MEMDIE clearing and makes sure that
no task queued for the oom reaper will keep it once it is processed
(either successfully or not).

Any feedback is highly appreciated.