Messages in this thread | | | From | James Sutherland <> | Subject | Re: Avoiding OOM on overcommit...? | Date | Wed, 22 Mar 2000 00:13:43 +0000 |
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On Tue, 21 Mar 2000 11:43:02 -0600 (CST), you wrote: >David Whysong <dwhysong@physics.ucsb.edu>: >> On Mon, 20 Mar 2000, Jesse Pollard wrote: >> >On Mon, 20 Mar 2000, David Whysong wrote: >> >> >> >>That's very misleading. In fact if you give the overcommitted system the >> >>same amount of VM, it will work just fine. In other words, turning off >> >>overcommit isn't what saves you. You added more memory! >> > >> >I guaranteed that the memory allocated could be used. I didn't just add >> >more memory. Just adding more memory will still allow the system to fail, >> >it may take longer, it may not happen as often. But it can still happen. >> >> If you properly handle system-wide OOM situations by killing tasks (see my >> other emails about doing this with the OOM killer patch + a userspace >> daemon), then you no longer have system crashes. >> >> Yes, your app can be killed, but that is also what happens with quotas. In >> fact, it happens earlier with quotas. > >It happens before the OOM can kill the system. It happens before my process >causes other users to loose theirs.
The shortage of memory cannot kill the system. It can just kill processes. A kernel bug can kill the system, but that's another issue.
>You obviously haven't used a large multiuser system recently. Quotas are >applied in almost every location I've seen. Why - to prevent one users >job from interfereing with other users jobs.
Quotas are essential, and I still can't see why Linux lacks them...
>If you were running a simulation/analysis and were supposedly given >resources to run, and I accessed the same system with the same goal in >mind, which user gets killed when I use up the resources given to me? >BTW, I have the same priority of access to the system that you have...
Yours, if you don't have enough resources available to you to run it. Otherwise, both run fine.
>Who gets killed - your process or mine? Yours, because there aren't enough resources to run it. >Which is the correct one? Yours, as above. >How do you know it is the correct one? Because it would put you above the limit available to you. >If it happens again, are the answers the same? Yes.
James.
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