From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Dibowitz Date: Tue, 26 Apr 2005 06:14:36 +0000 Subject: Re: udev and raw support Message-Id: <426DDC4C.6050006@ipom.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------enig45C4398C6A49B542F352D045" List-Id: References: <426CC269.5090400@ipom.com> In-Reply-To: <426CC269.5090400@ipom.com> To: linux-hotplug@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig45C4398C6A49B542F352D045 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Greg KH wrote: > I really don't know if they got that patch or not, sorry. What version of util-linux has that patch, do you know? Well http://www.kernel.org/pub/linux/utils/util-linux/ only goes up to q, so I'm guess that's it. I'll file a bug report, thanks. > Because you should use O_DIRECT to access block devices directly, which > properly uses the kernel io subsystems. raw goes around all of that, > and thinks it is smarter than the kernel. In the end, it is wrong, and > can be slower. Fair enough. Wouldn't it make sense to make a simple raw module that simply was equivalent to opening the block device with O_DIRECT if for no other reason than, erm, "backwards" compatiblity with other unices - for ease of the writers of mplayer/xine/ogle/etc.? > Anyway, you can get around this by creating the device node by hand if > you really want. I suggest you file a debian bug to get them to fix the > raw program to work properly with udev. I would be interested to experiment, even though I'm sure you're right... but I think I'm missing something... don't the major/minor number need to be the same: [phil@rider rc2.d]$ sudo mknod /dev/raw/raw1 c 22 0 [phil@rider rc2.d]$ sudo raw /dev/raw/raw1 /dev/hdc Device '/dev/raw/raw1' is not a raw dev [phil@rider rc2.d]$ ls -l /dev/raw/raw1 /dev/hdc brw-rw---- 1 root cdrom 22, 0 Apr 25 21:36 /dev/hdc crw-r--r-- 1 root root 22, 0 Apr 25 23:08 /dev/raw/raw1 -- Phil Dibowitz phil@ipom.com Freeware and Technical Pages Insanity Palace of Metallica http://www.phildev.net/ http://www.ipom.com/ "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin, 1759 --------------enig45C4398C6A49B542F352D045 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFCbdxMN5XoxaHnMrsRAtMvAJ483GMnVmMLRfRgJECjJ/WCybBbrACgmj24 +Sx4GIeXp2GPlGvxHHAgf1Y= =RwsR -----END PGP SIGNATURE----- --------------enig45C4398C6A49B542F352D045-- ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel