ad0: WARNING - WRITE_DMA interrupt was seen but timeout fired LBA=21267353

[Bjoern A. Zeeb]

On Wed, 12 May 2004, Søren Schmidt wrote:

> Bjoern A. Zeeb wrote:
> >>>Could someone tell me what this means (-CURRENT)?
> >>
> >>The WRITE operation was signalled done by the disk by issueing an
> >>interrupt and the finished request was put on a taskqueue to have it
> >>return status to the system. However the timeout code fired because the
> >>taskqueue hadn't been executed yet (it will wait one ome timeout period
> >>before the result is forced through)..
> >>
> >>So there is no harm done, but the taskqueue was slow to respond...
> >
> >
> > as postend to freebsd-amd64 I am getting far too many of those and
> > they won't stop.
> >
> >  From time to time there is also
> > ad10: WARNING - WRITE_DMA interrupt was seen but taskqueue stalled LBA=...
> > between all the ${subject} lines.
>
> Hmm, something is keeping the taskqueue busy, and its not ATA...

but the thing starts with ${subject} and only after some dozen logs
(multi monitor pages) I get one or two taskqueue stalled; afterwards
${subject} keeps scrolling again and everything starts from the
beginning.

Further more I can only reproduce it with heavy IO HDD traffic; it
doesn't happen for network trafic, it doesn't happen when only working
on a 512MB md0 memory disk I think. It happens once I copy sources to
HDD, have src or obj on HDD and compiling world.

The strange thing that made makes me thinking is that I also get it
when using atacontrol and set the channel to PIO0 BIOSPIO;

it's on amd64 with 5.2.1R; I am currently cross compiling HEAD for
that machine.

is there any way how I could get to know what's keeping the taskqueue
busy ? if scrolling starts no user interaction is possible anymore.

-- 
Bjoern A. Zeeb				bzeeb at Zabbadoz dot NeT
56 69 73 69 74				http://www.zabbadoz.net/