Re: [PATCH] oom_kill: use rss value instead of vm size for badness

From: KAMEZAWA Hiroyuki
Date: Thu Dec 03 2009 - 19:47:54 EST


On Thu, 3 Dec 2009 15:25:05 -0800 (PST)
David Rientjes <rientjes@xxxxxxxxxx> wrote:

> If Andrew pushes the patch to change the baseline to rss
> (oom_kill-use-rss-instead-of-vm-size-for-badness.patch) to Linus, I'll
> strongly nack it because you totally lack the ability to identify memory
> leakers as defined by userspace which should be the prime target for the
> oom killer. You have not addressed that problem, you've merely talked
> around it, and yet the patch unbelievably still sits in -mm.
>
It's still cook-time about oom-kill patches and I'll ask Andrew not to send
it when he asks in mm-merge plan. At least, per-mm swap counter and lowmem-rss
counter is necessary. I'll rewrite fork-bomb detector, too.

Repeatedly saying, calculating badness from vm_size _only_ is bad.
I'm not sure how google's magical applications works, but in general,
vm_size doesn't means private memory usage i.e. how well oom-killer can free
pages.
And current oom-killer kills wrong process. Please share your idea to making
oom-killer better rather than just saying "don't do that".

Do you have good algorithm for detecting memory-leaking process in user land ?
I think I added some in my old set but it's not enough.
I'll add more statistics to mm_struct to do better work.

BTW, I hate oom_adj very much. It's nature of "shift" is hard to understand.
I wonder why static oom priority or oom_threshold was not implemented...

Thanks,
-Kame

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/