Posted Mar 11, 2011 0:37 UTC (Fri) by droundy
In reply to: Memory overcommit
Parent article: Delaying the OOM killer
If you just overcommit memory, then when apps start using all the memory they allocated the system will become unstable and processes will be killed without warning by the OOM killer. It's clear which is preferable.
Surely you've run into the situation where you've been unable to log into a machine because it's swapping like crazy, and are thus unable to kill the offending process? Is that really preferable to being able to go in and fix things immediately? Of course, things are easier when you've got a desktop and are already logged in, but even then I've seen situations where just switching to a terminal took many, many minutes, not to suggest the possibility of opening a new terminal.
The large majority of OOM-killer experiences I've had have been situations where there was a memory leak involved. In such cases, the OOM killer is usually quite good at identifying the culprit and killing it. If you add enough swap, then the system freezes up indefinitely (or until you're able to get a killall typed into a terminal). Not a huge improvement in my book. In any case, it's not clear which is preferable.
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