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

Nick Piggin
2003-11-06T13:06:08Z

Jens Axboe wrote:

>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.
>

Although have a look at the interrupts field in vmstat 1255, 725, 736 ...

>
>>I guess its over to Andrew.
>>
>
>Back to you, Kent! :-)
>

:)