Re: 2.6.20-rc5: cp 18gb 18gb.2 = OOM killer, reproducible just like 2.16.19.2

Bill Cizek
2007-01-25T01:27:57Z

Justin Piszcz wrote:
> On Mon, 22 Jan 2007, Andrew Morton wrote:
>
>>> On Sun, 21 Jan 2007 14:27:34 -0500 (EST) Justin Piszcz <jpiszcz@lucidpixels.com> wrote:
>>> Why does copying an 18GB on a 74GB raptor raid1 cause the kernel to invoke
>>> the OOM killer and kill all of my processes?
>>>
> Running with PREEMPT OFF lets me copy the file!! The machine LAGS
> occasionally every 5-30-60 seconds or so VERY BADLY, talking 5-10 seconds
> of lag, but hey, it does not crash!! I will boot the older kernel with
> preempt on and see if I can get you that information you requested.
>
Justin,

According to your kernel_ring_buffer.txt (attached to another email),
you are using "anticipatory" as your io scheduler:
289 Jan 24 18:35:25 p34 kernel: [ 0.142130] io scheduler noop
registered
290 Jan 24 18:35:25 p34 kernel: [ 0.142194] io scheduler
anticipatory registered (default)

I had a problem with this scheduler where my system would occasionally
lockup during heavy I/O. Sometimes it would fix itself, sometimes I had
to reboot. I changed to the "CFQ" io scheduler and my system has worked
fine since then.

CFQ has to be built into the kernel (under BlockLayer/IOSchedulers). It
can be selected as default or you can set it during runtime:

echo cfq > /sys/block/<disk>/queue/scheduler
...

Hope this helps,
Bill