From: Andrea Arcangeli <andrea@novell.com>
To: Greg KH <greg@kroah.com>
Cc: "Marco d'Itri" <md@Linux.IT>,
"Giacomo A. Catenazzi" <cate@pixelized.ch>,
linux-kernel@vger.kernel.org
Subject: Re: udev is too slow creating devices
Date: Wed, 15 Sep 2004 21:21:34 +0200 [thread overview]
Message-ID: <20040915192134.GA4197@dualathlon.random> (raw)
In-Reply-To: <20040915161541.GD21971@kroah.com>
On Wed, Sep 15, 2004 at 09:15:41AM -0700, Greg KH wrote:
> But the low level driver (like a USB driver for example), has no way of
> knowing when the "device discovery" process is over. Actually the USB
> core never knows this either, as devices come and go all the time.
eventually the discovery will end with a call into userspace, it'd be
enough to wait4 and wakeup a waitqueue when the wait4 returns.
> So the kernel can not know what or when to wait for something it doesn't
> know is going to ever happen in the future.
the kernel certainly knows when it's about time to fork an userspace
process to create the device, doesn't it? then just wait4 while the
process is running.
> Remember, this isn't your old "static device tree" unix-like kernel that
> people grew up with, anymore. :)
if you intentionally don't want to provide serialization and force into
/var/run locking, that's fine with me, but I don't buy your claim that
it's not feasible.
next prev parent reply other threads:[~2004-09-15 19:23 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-14 18:33 udev is too slow creating devices Giacomo A. Catenazzi
2004-09-14 18:42 ` Greg KH
2004-09-14 19:21 ` Chris Meadors
2004-09-14 19:40 ` Chris Friesen
2004-09-14 19:52 ` Greg KH
2004-09-14 20:00 ` Chris Friesen
2004-09-14 20:43 ` Giacomo A. Catenazzi
2004-09-14 21:35 ` Greg KH
2004-09-14 21:45 ` Marco d'Itri
2004-09-14 21:51 ` Greg KH
2004-09-14 22:47 ` Andrea Arcangeli
2004-09-14 23:04 ` Greg KH
2004-09-14 23:20 ` Andrea Arcangeli
2004-09-14 23:34 ` Gianni Tedesco
2004-09-14 23:58 ` Andrea Arcangeli
2004-09-15 16:15 ` Greg KH
2004-09-15 19:21 ` Andrea Arcangeli [this message]
2004-09-15 22:09 ` Chris Friesen
2004-09-15 22:15 ` Andrea Arcangeli
2004-09-15 22:25 ` Greg KH
2004-09-15 22:23 ` Greg KH
2004-09-15 22:46 ` Andrea Arcangeli
2004-09-15 13:55 ` Giacomo A. Catenazzi
2004-09-15 14:36 ` Ian Campbell
2004-09-15 15:20 ` Tonnerre
2004-09-15 15:45 ` Giacomo A. Catenazzi
2004-09-15 16:12 ` Greg KH
2004-09-15 16:51 ` Marc Ballarin
2004-09-15 18:00 ` Greg KH
2004-09-19 16:51 ` Jon Masters
2004-09-19 18:53 ` Andreas Jellinghaus
2004-09-20 2:16 ` Alexander E. Patrakov
2004-09-17 8:06 ` Alexander E. Patrakov
2004-09-15 16:11 ` Greg KH
2004-09-15 16:09 ` Greg KH
2004-09-17 7:48 ` Alexander E. Patrakov
2004-09-14 22:03 ` Marc Ballarin
[not found] <http://lkml.org/lkml/2004/9/14/316@localhost.localdomain>
2004-09-14 20:30 ` Michael Thonke
[not found] <http://lkml.org/lkml/2004/9/15/119@localhost.localdomain>
2004-09-15 14:26 ` Michael Thonke
-- strict thread matches above, loose matches on Subject: below --
2004-09-18 19:25 Ihar 'Philips' Filipau
2004-09-18 21:24 ` Greg KH
2004-09-18 19:44 Ihar 'Philips' Filipau
2004-09-18 20:37 ` Marc Ballarin
2004-09-18 21:30 ` Greg KH
2004-09-19 0:06 ` Ihar 'Philips' Filipau
2004-09-19 0:41 ` Greg KH
2004-09-19 8:18 ` Ihar 'Philips' Filipau
2004-09-20 4:19 ` Greg KH
2004-09-19 4:38 ` Benjamin Herrenschmidt
2004-09-19 8:27 ` Ihar 'Philips' Filipau
2004-09-19 11:53 ` Alexander E. Patrakov
2004-09-19 17:32 ` Greg KH
2004-09-19 18:43 ` Grzegorz Kulewski
2004-09-20 4:11 ` Greg KH
2004-09-20 10:52 ` Jon Masters
2004-09-19 12:00 ` Marc Ballarin
2004-09-19 14:25 ` Ihar 'Philips' Filipau
2004-09-19 15:14 ` Marc Ballarin
2004-09-19 16:00 ` Alexander E. Patrakov
2004-09-19 17:11 ` Marc Ballarin
2004-09-19 17:30 ` Greg KH
2004-09-20 2:29 ` Alexander E. Patrakov
2004-09-20 16:17 ` Giacomo A. Catenazzi
2004-09-29 23:38 ` Randy.Dunlap
2004-09-29 23:53 ` Greg KH
2004-09-19 19:40 ` Ihar 'Philips' Filipau
2004-09-20 0:05 ` Kyle Moffett
2004-09-20 4:06 ` Greg KH
2004-09-20 8:54 ` Marc Ballarin
2004-09-20 0:03 ` Benjamin Herrenschmidt
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