Re: unwanted disk access by the kernel?

Andrew Morton
2002-03-15T07:03:03Z

Dan Maas wrote:
>
> I've been trying to set up my laptop for mobile use. I'm having a
> problem with unwanted disk activity - even when the system is
> completely idle, there is still an occasional trickle of disk writes
> (which prevents the poor hard drive from ever spinning down).
>
> Yes, I thought this was a user-space issue too - but even booting into
> a bare-bones root environment does not stop the occasional disk
> access! Here is everything that's left:

Are all filesystems mounted with the `noatime' mount option?

> PID USER VSZ RSS TIME STAT COMMAND WCHAN
> 7 root 0 0 00:00:00 SW [kupdated] kupdate
> 6 root 0 0 00:00:00 SW [bdflush] bdflush
> 5 root 0 0 00:00:00 SW [kswapd] kswapd
> 4 root 0 0 00:00:00 SWN [ksoftirqd_CPU0] ksoftirqd
> 1 root 1316 524 00:00:05 S init [S] select
> 2 root 0 0 00:00:00 SW [keventd] context_thread
> 3 root 0 0 00:00:00 SW [kapmd] apm_mainloop
> 8 root 0 0 00:00:00 Z [khubd <defunct> exit

eww. Does khubd always do that? Does this patch make it behave?

--- linux-2.4.19-pre3/drivers/usb/hub.c Mon Mar 11 14:53:21 2002
+++ linux-akpm/drivers/usb/hub.c Thu Mar 14 22:59:17 2002
@@ -908,6 +908,7 @@ static int usb_hub_thread(void *__hub)
*/

daemonize();
+ reparent_to_init();

/* Setup a nice name */
strcpy(current->comm, "khubd");

-