Re: 2.4.20: Proccess stuck in __lock_page ...

Jens Axboe
2003-05-28T14:20:42Z

On Wed, May 28 2003, Chris Mason wrote:
> On Wed, 2003-05-28 at 09:08, Jens Axboe wrote:
> >
> > > > May I ask how you are reproducing the bad results? I'm trying in vain
> > > > here...
> > >
> > > Quoting Con Kolivas:
> > >
> > > dd if=/dev/zero of=dump bs=4096 count=512000
> >
> > already tried that, no go. on ide/scsi? what filesystem? how much ram?
> > anything else running? smp/up?
>
> I think we've got a few different problems. On SMP boxes, you need to
> have the fix-pausing patch from andrea applied to catch all the corner
> cases.

Agree

>
> On UP boxes it's possible the requests are starving in the drive, SCSI
> users should try with the max tags set down to something sensible,
> between 8 and 32.
>
> IDE people can try lowering the max_kb_per_request paramater in
> /proc/ide/<drive>/settings, but this should only affect starvation with
> the writeback cache on.
>
> I made a patch a while ago that timed how long people spent waiting in
> __get_request_wait, it might help us figure out where the starvation is
> really happening.

But this seems totally unrelated to the reported problems, we are
talking about complete stalls of the mouse. No amount of io starvation
should provoke something like that.

--
Jens Axboe