Messages in this thread | | | Date | Tue, 5 Jun 2007 16:16:09 -0700 (PDT) | From | David Rientjes <> | Subject | Re: [patch] cpusets: do not allow TIF_MEMDIE tasks to allocate globally |
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On Tue, 5 Jun 2007, Paul Jackson wrote:
> I'm a little surprised at this suggested change -- I'd have thought > that it was a good idea to let tasks marked for extinction get memory > anywhere, as they were going to use that memory to exit, and free up > lots more memory. >
The intended purpose of TIF_MEMDIE was to allocate pages without being bound by the watermarks so that they have access to memory reserves on the per-zone level. If the cpuset doesn't have access to a zone, whether it's memory reserve or not, it shouldn't allocate there.
> I'm pretty sure we have this same policy in other places in the > kernel, besides cpusets. Did you intend to change them too? >
You'd have to cite them first.
> If a MEMDIE task is taking enough memory to OOM other tasks anywhere > in the system, then doesn't that mean your entire system was in deep > yogurt, and we're just haggling over who to blame for the upcoming > crash? >
No, it means that it can allocate anywhere based on the zonelist ordering and then can OOM a very small exclusive cpuset that would never have had any memory pressure if it wasn't violated.
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