The OOM killer sets the TIF_MEMDIE thread flag for its victims to alert
other kernel code that the current process was killed due to memory
pressure, and needs to finish whatever it's doing quickly. In the page
allocator this allows victim processes to quickly allocate memory using
emergency reserves. This is especially important when memory pressure is
high; if all processes are taking a while to allocate memory, then our
victim processes will face the same problem and can potentially get
stuck in the page allocator for a while rather than die expeditiously.
To ensure that victim processes die quickly, set TIF_MEMDIE for the
entire victim thread group.
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
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