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On Wed, 2005-07-06 at 15:46 -0700, Greg KH wrote: |
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> Ok, now that devfs is removed from the 2.6 kernel tree[1], I think it's |
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> time to start to revisit some of the /dev naming rules that we currently |
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> are living with[2]. |
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> |
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> To start with, the 061 version of udev offers a big memory savings if |
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> you use the "default" kernel name of a device[3]. If you do that, it does |
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> not create a file in its database in /dev/.udevdb/ |
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> |
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> If we can move away from some of our devfs-like names, we stand to |
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> reclaim a lot of memory from everyone's machines. As an example, if we |
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> drop all of the tty/pts/vc/vcc symlinks, and just go with the default |
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> kernel name, we save 2.5Mb of space in tempfs/ramfs. I've done this on |
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> my machines and everything seems to work just fine (it looks like |
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> everything that was trying to use a tty node was just using the symlink |
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> anyway.) |
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> |
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> So, anyone have any objections to me changing the default udev naming |
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> scheme in this manner? |
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> |
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Fine with me. I assume we will need to keep the rcscript support for |
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those die-hard 2.4 users still, but hopefully we can eventually drop |
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that as well. |
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> Next up, that loony block device naming scheme (more on that later...) |
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> |
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Heh. I hope that we will still at least just do the cdsymlinks stuff |
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(just the /dev/cdrom, /dev/dvd, etc stuff) as that do make things a bit |
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easier for multimedia stuff. |
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> [3] HAL needs a patch to be able to handle this. It's posted on the |
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> hal development mailing lists and will be checked in real-soon-now. |
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I just think we need to make sure this is in first ... |
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Lastly on an unrelated note ... I have a rule: |
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----- |
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# cat /etc/udev/rules.d/40-dm.rules |
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KERNEL="dm-[0-9]*", PROGRAM="/sbin/devmap_name %M %m", NAME="mapper/%c", SYMLINK="%c" |
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----- |
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And in theory it should be the last rule to set the name ... however the |
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default one in 50-udev.rules overrides it, and I have to add |
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OPTIONS="last_rule" |
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--- (default rule) --- |
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KERNEL="dm-[0-9]*", NAME="" |
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---------------------- |
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I am assuming (without having looked at the code) that because NAME is |
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set to "", whatever code that should drop it as it have NAME, does not |
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kick in? |
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Thanks, |
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|
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-- |
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Martin Schlemmer |
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Gentoo Linux Developer, Desktop/System Team Developer |
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Cape Town, South Africa |
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