Re: What to do about the 2TB limit on HDIO_GETGEO ?

From: Kay Sievers
Date: Thu Mar 27 2008 - 15:04:25 EST


On Thu, 2008-03-27 at 11:55 -0700, H. Peter Anvin wrote:
> Kay Sievers wrote:
> >>
> >> And it's not just a few 10s of lines of code currently,
> >> but rather about 80-100 lines just to find the correct device subdir,
> >> and *then* a few more 10s of lines of code to retrieve the value.
> >
> > Hmm, 100 lines? What else do you need?
> >
> > $ grep -l 8:3 /sys/class/block/*/dev
> > /sys/class/block/sdc/dev
> >
>
> That's particularly funny, because your very own example gives the wrong
> result -- sdc is 8:32 not 8:3 (which is sdc3, which is also excluded by
> your search.)

Very true, but I guess you get the idea, and know how to add the proper
string match to grep. :)

> Not to mention the fact that it is still O(n).

Any real numbers from a large setup, which show that we want to have a
reverse devnum map in sysfs?

Thanks,
Kay

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