Re: [patch -mm 08/18] oom: badness heuristic rewrite

[David Rientjes <rientjes@google.com>]

On Wed, 2 Jun 2010, KOSAKI Motohiro wrote:

> > I'm glad you asked that because some recent conversation has been 
> > slightly confusing to me about how this affects the desktop; this rewrite 
> > significantly improves the oom killer's response for desktop users.  The 
> > core ideas were developed in the thread from this mailing list back in 
> > February called "Improving OOM killer" at 
> > http://marc.info/?t=126506191200004&r=4&w=2 -- users constantly report 
> > that vital system tasks such as kdeinit are killed whenever a memory 
> > hogging task is forked either intentionally or unintentionally.  I argued 
> > for a while that KDE should be taking proper precautions by adjusting its 
> > own oom_adj score and that of its forked children as it's an inherited 
> > value, but I was eventually convinced that an overall improvement to the 
> > heuristic must be made to kill a task that was known to free a large 
> > amount of memory that is resident in RAM and that we have a consistent way 
> > of defining oom priorities when a task is run uncontained and when it is a 
> > member of a memcg or cpuset (or even mempolicy now), even in the case when 
> > it's contained out from under the task's knowledge.  When faced with 
> > memory pressure from an out of control or memory hogging task on the 
> > desktop, the oom killer now kills it instead of a vital task such as an X 
> > server (and oracle, webserver, etc on server platforms) because of the use 
> > of the task's rss instead of total_vm statistic.
> 
> The above story teach us oom-killer need some improvement. but it haven't
> prove your patches are correct solution. that's why you got to ask testing way.
> 

I would consider what I said above, "when faced with memory pressure from 
an out of control or memory hogging task on the desktop, the oom killer 
now kills it instead of a vital task such as an X server because of the 
use of the task's rss instead of total_vm statistic" as an improvement 
over killing X in those cases which it currently does.  How do you 
disagree?

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