Hi, this is a part of a larger series I posted back in Oct last year [1]. I have dropped patch 3 because it was incorrect and patch 4 is not applicable without it.
The primary reason to apply patch 1 is to remove a risk of the complete memory depletion by oom victims. While this is a theoretical risk right now there is a demand for memcg aware oom killer which might kill all processes inside a memcg which can be a lot of tasks. That would make the risk quite real. This issue is addressed by limiting access to memory reserves. We no longer use TIF_MEMDIE to grant the access and use tsk_is_oom_victim instead. See Patch 1 for more details. Patch 2 is a trivial follow up cleanup. I would still like to get rid of TIF_MEMDIE completely but I do not have time to do it now and it is not a pressing issue. [1] http://lkml.kernel.org/r/20161004090009.7974-1-mho...@kernel.org
