Re: SATA exceptions with 2.6.20-rc5

From: Jens Axboe
Date: Sun Jan 14 2007 - 21:53:37 EST


On Sun, Jan 14 2007, Robert Hancock wrote:
> Jeff Garzik wrote:
> >>Looks like all of these errors are from a FLUSH CACHE command and the
> >>drive is indicating that it is no longer busy, so presumably done.
> >>That's not a DMA-mapped command, so it wouldn't go through the ADMA
> >>machinery and I wouldn't have expected this to be handled any
> >>differently from before. Curious..
> >
> >It's possible the flush-cache command takes longer than 30 seconds, if
> >the cache is large, contents are discontiguous, etc. It's a
> >pathological case, but possible.
> >
> >Or maybe flush-cache doesn't get a 30 second timeout, and it should...?
> > (thinking out loud)
> >
> > Jeff
>
> If the flush was still in progress I would expect Busy to still be set,
> however..

I'd be surprised if the device would not obey the 7 second timeout rule
that seems to be set in stone and not allow more dirty in-drive cache
than it could flush out in approximately that time.

And BUSY should also be set for that case, as Robert indicates.

--
Jens Axboe

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