Messages in this thread |  | | | Date | Tue, 3 Nov 2009 12:49:52 -0800 (PST) | | From | David Rientjes <> | | Subject | Re: Memory overcommit |
On Fri, 30 Oct 2009, KAMEZAWA Hiroyuki wrote:
> > > - The kernel can't know the program is bad or not. just guess it. > > > > Totally irrelevant, given your fourth point about /proc/pid/oom_adj. We > > can tell the kernel what we'd like the oom killer behavior should be if > > the situation arises. > > > > My point is that the server cannot distinguish memory leak from intentional > memory usage. No other than that. >
That's a different point. Today, we can influence the badness score of any user thread to prioritize oom killing from userspace and that can be done regardless of whether there's a memory leaker, a fork bomber, etc. The priority based oom killing is important to production scenarios and cannot be replaced by a heuristic that works everytime if it cannot be influenced by userspace.
A spike in memory consumption when a process is initially forked would be defined as a memory leaker in your quiet_time model.
> In this summer, at lunch with a daily linux user, I was said > "you, enterprise guys, don't consider desktop or laptop problem at all." > yes, I use only servers. My customer uses server, too. My first priority > is always on server users. > But, for this time, I wrote reply to Vedran and try to fix desktop problem. > Even if current logic works well for servers, "KDE/GNOME is killed" problem > seems to be serious. And this may be a problem for EMBEDED people, I guess. >
You argued before that the problem wasn't specific to X (after I said you could protect it very trivially with /proc/pid/oom_adj set to OOM_DISABLE), but that's now your reasoning for rewriting the oom killer heuristics?
> I can say the same thing to total_vm size. total_vm size doesn't include any > good information for oom situation. And tweaking based on that not-useful > parameter will make things worse. >
Tweaking on the heuristic will probably make it more convoluted and overall worse, I agree. But it's a more stable baseline than rss from which we can set oom killing priorities from userspace.
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