Memory exclusivity with respect to cpusets should guarantee that memory
nodes do not overlap with siblings if they are marked with mems_exclusive.
The patch simply preserves that behavior through the time period between
when the OOM killer issues a SIGKILL and the task is exiting and marked
with PF_EXITING.
Obviously GFP_KERNEL allocations can allocate regardless of our memory
exclusivity, but the point is that a job in one exclusive cpuset should
not have the ability to effect the performance (in terms of reclaim and
swap), memory usage, or survival of jobs in other exclusive cpusets
because it was out of memory.
But it's a reality that we need to respect. It happens and when it does
it has the potential to hamper other cpusets that we setup to be exclusive
themselves.
David
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