From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Subject: Re: What to do about the 2TB limit on HDIO_GETGEO ? Date: Thu, 27 Mar 2008 20:03:05 +0100 Message-ID: <1206644585.24291.4.camel@lov.site> References: <47E875AD.1000901@rtr.ca> <47E87942.2020409@rtr.ca> <47E88A13.70808@zytor.com> <47E90019.3050006@rtr.ca> <47E90458.7030801@zytor.com> <47E9383F.3050908@rtr.ca> <20080325192515.GA24234@suse.de> <47E99A02.7040903@rtr.ca> <3ae72650803271151k5a7b5c4cn5078b3bdf6a9c87a@mail.gmail.com> <47EBED9B.8020706@zytor.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <47EBED9B.8020706@zytor.com> Sender: linux-scsi-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Mark Lord , Greg KH , Jens Axboe , Jeff Garzik , Tejun Heo , Linus Torvalds , Andrew Morton , Linux Kernel , IDE/ATA development list , linux-scsi List-Id: linux-ide@vger.kernel.org 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