Re: A new ide warning message

From: Stephen Lord (
Date: Fri Aug 02 2002 - 07:05:38 EST

On Fri, 2002-08-02 at 06:48, Marcin Dalecki wrote:
> Uz.ytkownik Jens Axboe napisa?:
> > On Fri, Aug 02 2002, Stephen Lord wrote:
> >
> >>In 2.5.30 I started getting these warning messages out ide during
> >>the mount of an XFS filesystem:
> >>
> >>ide-dma: received 1 phys segments, build 2
> >>
> >>Can anyone translate that into English please.
> >
> >
> > Well I added that message when switching to the 2.5 style request
> > mapping functions, and I think the message is perfectly clear :-). Never
> > the less, it means that a segment that came into the ide layer with an
> > advertised size of 1 segment was returned from blk_rq_map_sg() as having
> > _two_. This can be a problem with dynamically allocated sg table (not
> > that ide uses those, but still).
> >
> > It's a bug and usually a critical one when this happens. I'd be inclined
> > to think that Adam's changes in this path are to blame for this error.
> Carefull carefull. it can be that the generic BIO code doesn't honour
> the limits Adam was setting properly. And it can be of course
> as well the XFS doesn't cooperate properly with those limits as well,
> since ther kernel appears to be patched to support them.

Well, this is happening when reading the log up from disk during
mount, we will be asking for somewhere around 32K of data at a
time, but it might not be well aligned. I will instrument it and
report back - will be a few hours, the box is at work and I just
tripped it up in some other code, I cannot reset it from here.

> It would be helpfull as well to know on which brand of host controller
> chip this was found. In esp. trm290 maybe?

Since it is down I cannot give you the ide boot messages right now,
but it is a Tyan Tiger BX motherboard using the built in IDE chipset,
so pretty generic stuff.

> >
> > Oh, and I'd be _really_ careful if you have trusted data on that drive
> > (surely not when running 2.5 ide on it :-)
> >

It's a scratch box, all it does is run development kernels and tests,
I am keeping 2.5 in a cage right now.

To answer your other question Jens, yes I can reproduce at will,
once I go in to the office.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:18 EST