Re: Unkillable processes stuck in "D" state running forever

Denis Vlasenko (
Sun, 28 Jul 2002 16:09:33 -0200

On 28 July 2002 09:35, Federico Sevilla III wrote:
> On Sun, Jul 28, 2002 at 06:22:46PM +0800, Federico Sevilla III wrote:
> > I have been noticing problems on two of my boxes here with some
> > processes somehow getting stuck in "D" state, which cannot be killed
> > even by a SIGKILL by root, and stay on running forever. I have noticed
> > the problem, so far, on 2.4.18-xfs and 2.4.19-rc2-xfs kernels.
> I do not know how small a tidbit this will be, but together with these
> processes stuck in state "D", there is a continuing rise in the load
> averages of the system as reported by various interfaces
> (top/uptime/w/phpSysInfo). On the system running 2.4.18-xfs this rose to
> up to 25 before I eventually rebooted the box.
> Another bit: on the 2.4.18-xfs box, the number of processes getting
> stuck in state "D" kept growing. Various `ps ax` and `sync` processes in
> particular, would get stuck and stall as I would issue them. It may be
> interesting to note that with 2.4.19-rc2-xfs, with which I had my "latest
> encounter" with this problem, no `ps ax` or `sync` processes got stuck.
> Only the couple of apt-method processes that got stuck (and any new ones
> I would launch in an attempt to download a package from the Internet for
> installation) were there.

D state processes are sitting in kernel code waiting for something
to happen. It is ok to sit in D state for milliseconds, it is acceptable
to sit for seconds. If those processes are stuck forever, it's a bug.

Capture Alt-SysRq-T output and ksymoops relevant part
Yes it means you should have ksymoops installed and tested,
which is easy to get wrong. I've done that too often.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at