Messages in this thread | | | Date | Tue, 16 Feb 2010 18:28:05 -0800 (PST) | From | David Rientjes <> | Subject | Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on_oom mode |
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On Wed, 17 Feb 2010, KAMEZAWA Hiroyuki wrote:
> > What do you think about making pagefaults use out_of_memory() directly and > > respecting the sysctl_panic_on_oom settings? > > > > I don't think this patch is good. Because several memcg can > cause oom at the same time independently, system-wide oom locking is > unsuitable. BTW, what I doubt is much more fundamental thing. >
We want to lock all populated zones with ZONE_OOM_LOCKED to avoid needlessly killing more than one task regardless of how many memcgs are oom.
> What I doubt at most is "why VM_FAULT_OOM is necessary ? or why we have > to call oom_killer when page fault returns it". > Is there someone who returns VM_FAULT_OOM without calling page allocator > and oom-killer helps something in such situation ? >
Before we invoked the oom killer for VM_FAULT_OOM, we simply sent a SIGKILL to current because we simply don't have memory to fault the page in, it's better to select a memory-hogging task to kill based on badness() than to constantly kill current which may not help in the long term.
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