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by zbentley 28 days ago
Yeah, crash ballast is an extremely underrated tool.

It also works for the OOM killer: run a daemon with a child process that holds some fixed amount of memory. Adjust OOM scores of everything else on the system lower than the child. If the parent’s waitpid() returns due to an OOM kill, send an alert/shutdown nonessentials/sync buffers to disk and so on.
1 comments
man8alexd 28 days ago
Maybe you should skip running a useless child process and just use PSI to monitor memory pressure.
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zbentley 28 days ago
PSI polling is also good, but there’s no substitute for knowing for sure that the OOM killer is awake and hunting.
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man8alexd 28 days ago
You can't know when the OOM killer is awake and hunting. The kernel doesn't know that.
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zbentley 28 days ago
The approach I originally described provides a useful early warning system for that condition. It’s not perfect, but has proven useful and better than nothing many times.
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