Re: oom killer gone nuts

[Jens Axboe <axboe@suse.de>]

On Thu, Jan 20 2005, Andrea Arcangeli wrote:
> On Thu, Jan 20, 2005 at 02:15:56PM +0100, Andries Brouwer wrote:
> > On Thu, Jan 20, 2005 at 01:34:06PM +0100, Jens Axboe wrote:
> > 
> > > Using current BK on my x86-64 workstation, it went completely nuts today
> > > killing tasks left and right with oodles of free memory available.
> > 
> > Yes, the fact that the oom-killer exists is a serious problem.
> > People work on trying to tune it, instead of just removing it.
> 
> I'm working on fixing it, not just tuning it. The bugs in mainline
> aren't about the selection algorithm (which is normally what people
> calls oom killer). The bugs in mainline are about being able to kill a
> task reliably, regardless of which task we pick, and every linux kernel
> out there has always killed some task when it was oom. So the bugs are
> just obvious regressions of 2.6 if compared to 2.4.
> 
> But this is all fixed now, I'm starting sending the first patches to
> Anderw very shortly (last week there was still the oracle stuff going
> on). Now I can fix the rejects.
> 
> I will guarantee nothing about which task will be picked (that's the old
> code at works, I changed not a bit in what normally people calls "the oom
> killer", plus the recent improvement from Thomas), but I guarantee the
> VM won't kill tasks right and left like it does now (i.e. by invoking the
> oom killer multiple times).

And especially not with 500MB of zone normal free, thanks :)

2.6.11-rc1-xx vm behaviour is looking a _lot_ worse than 2.6.10 btw, I
haven't looked closer at what has changed yet it's just a subjective
feeling. I regularly have to run a fillmem.c hog to prune caches or it
runs like an old dog.

-- 
Jens Axboe