[ adding Neil to the cc ] On Tue, Mar 25, 2008 at 2:26 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: > Greg KH wrote: > > On Tue, Mar 25, 2008 at 01:36:51PM -0700, H. Peter Anvin wrote: > >> Randy Dunlap wrote: > >>>> Come on people, adding symlinks for device major:minor numbers in sysfs > >>>> to save a few 10s of lines of userspace code? Can things get sillier? > >>>> > >>>> You can add a single udev rule to probably build these in a tree in /dev > >>>> if you really need such a thing... > >>>> > >>>> And what's wrong with your new ioctl recomendation? > >>> Ah, there's some sanity. :) > >> It's not so much an issue of a few tens of lines of user space code, but > >> rather the fact that something that should be O(1) is currently O(n). > > > > "should"? why? Is this some new requirement that everyone needs? I've > > _never_ seen anyone ask for the ability to find sysfs devices by > > major:minor number in O(1) time. Is this somehow a place where such > > optimization is warranted? > > Well, when dealing with shell scripts a O(n) very easily becomes O(n^2). > For the stuff that I, personally, do, it's not a big deal, but people > with large number of disks have serious gripes with our boot times. > I will jump in here to point out there would be another user of such an interface. Neil proposed an ioctl to retrieve the sysfs path of a device as part of his md support for external metadata. Neil's initial patch: http://marc.info/?l=linux-raid&m=119761445714319&w=2 My attempt to push things along: http://marc.info/?l=linux-kernel&m=120132398120816&w=2 -- Dan -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
