From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Dake Date: Fri, 11 Apr 2003 22:43:12 +0000 Subject: Re: [ANNOUNCE] udev 0.1 release Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-hotplug@vger.kernel.org Lars Marowsky-Bree wrote: >On 2003-04-11T15:30:21, > Steven Dake said: > > =20 > >>There is no "spec" that states this is a requirement, however, telecom=20 >>customers require the elapsed time from the time they request the disk=20 >>to be used, to the disk being usable by the operating system to be 20 mse= c. >> =20 >> > >Heh. Yes, I've read that spec, and some of it involves some good crack smo= king >;-) The current Linux scheduler will make that rather hard for you, you'll >need hard realtime for such guarantees. > Its quite easy to do if you are not dependent upon spawning an entire=20 process to execute the insertion and creation even of the device node. > > =20 > >>Its even more helpful for their applications if the call that hotswap=20 >>inserts blocks until the device is actually ready to use and available=20 >>in the filesystem. Another requirement of any system that attempts to=20 >>replace devfs would be this capability (vs constantly checking for the=20 >>device in the filesystem). >> =20 >> > >Uh. Can you please clarify? > >You want open(/dev/not_there_yet) to block until /dev/not_there_yet is >inserted? But if it is not inserted, the device file does not exist yet, so >the open() will simply return a ENOENT. > >The application (or a library, providing this capability you want) could >interact with the hotplug subsystem to be notified when this device is >inserted. > > >Sincerely, > Lars Marowsky-Br=E9e > > =20 > ------------------------------------------------------- This SF.net email is sponsored by: Etnus, makers of TotalView, The debugger= =20 for complex code. Debugging C/C++ programs can leave you feeling lost and=20 disoriented. TotalView can help you find your way. Available on major UNIX = and Linux platforms. Try it free. www.etnus.com _______________________________________________ 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