Re: SATA exceptions with 2.6.20-rc5

[Robert Hancock]

Jens Axboe wrote:
> On Mon, Jan 15 2007, Jeff Garzik wrote:
> > Jens Axboe wrote:
> > > 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.
> > AFAIK Windows flush-cache timeout is 30 seconds, not 7 as with other 
> > commands...
>
> Ok, 7 seconds for FLUSH_CACHE would have been nice for us too though, as
> it would pretty much guarentee lower latencies for random writes and
> write back caching. The concern is the barrier code, of course. I guess
> I should do some timings on potential worst case patterns some day. Alan
> may have done that sometime in the past, iirc.

Note that the ATA-7 spec for FLUSH CACHE says that "This command may 
take longer than 30 s to complete."

--
Robert Hancock      Saskatoon, SK, Canada
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Home Page: http://www.roberthancock.com/

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