Re: 2.9test9-mm1 and DAO ATAPI cd-burning corrupt

[Jens Axboe <axboe@suse.de>]

On Thu, Nov 06 2003, Nick Piggin wrote:
> 
> 
> Prakash K. Cheemplavam wrote:
> 
> >>>procs -----------memory---------- ---swap-- -----io---- --system-- 
> >>>----cpu----
> >>>r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us 
> >>>sy id wa
> >>>2  0      0 579472  13976 308572    0    0   425    85 1255   645  5 
> >>>3 84  9
> >>>2  0      0 579456  13976 308572    0    0     0     0  725   521  5 
> >>>5 91  0
> >>>1  0      0 579448  13976 308572    0    0     0     0  736   523  2 
> >>>5 94  0
> >>>0  0      0 579448  13976 308572    0    0     0    25  745   439  2 
> >>
> >>
> >>
> >>[snip]
> >>
> >>This looks good, from a system utilization point of view. I'm wondering
> >>whether you have the iso image cached? There's no block io going on.
> >>
> >>It does like more like a CPU scheduler problem at this point.
> >
> >
> >
> >Ok, then it is Nick's turn, I guess. :-) Yeah most probably the iso is 
> >cached, as it was not the first time I burnt the iso when I did the 
> >vmstat, furthermore I have 1 GB of RAM... The other thing which 
> >doesn't speack for i/o problems, I guess: Just the first seconds when 
> >I start erasing the CD-RW the mouse hangs and heavily stutters, then 
> >it is OK until actual burning of image begins, then the mouse slightly 
> >stutters. All this was not with test9-mm1.
> >
> 
> I don't think the scheduler is the problem if you didn't have these problems
> in mm1. The scheduler is quite good when nothing is reniced. Whats funny
> though is it looks like you're losing timer interrupts, this is a sign that
> something is holding interrupts off for too long, and would also cause
> problems with your mouse.

sys time is usually pretty high if that is the case, and it's hovering
around 5% here... Prakash, are you sure that dma is enabled on the
drive? When you see the problem, do a vmstat 1 for 10 seconds so you are
absolutely sure you are sending the info from when the problem occurs.

> I guess its over to Andrew.

Back to you, Kent! :-)

-- 
Jens Axboe