From: Kay Sievers <kay.sievers@vrfy.org>
To: linux-hotplug@vger.kernel.org
Subject: Re: Udev incompatibility with qemu and bochs
Date: Wed, 19 Oct 2005 18:05:36 +0000 [thread overview]
Message-ID: <20051019180536.GC21028@vrfy.org> (raw)
In-Reply-To: <43560651.9090802@ums.usu.ru>
On Wed, Oct 19, 2005 at 10:45:55AM -0700, Greg KH wrote:
> On Wed, Oct 19, 2005 at 02:39:45PM +0600, Alexander E. Patrakov wrote:
> > UDEV_ALARM_TIMEOUT is defined to 120 seconds in udev.h. The problem is
> > that it does take 2 minutes to populate /dev inside slow emulators like
> > qemu or bochs, especially when the emulated and host CPU types differ
> > and udev rules include RUN+=/sbin/udev_run_hotplugd. The reason is that
> > inside those emulators exec() is very expensive (involves
> > jit-compilation from one sort of machine code to another). Please
> > provide an option to disable this alarm. The preferred form would be an
> > environment variable, so that I can type "linux UDEV_NO_ALARM=1" at the
> > boot prompt inside the emulator and see the system booting normally.
>
> Feel free to provide such a patch, if you need it.
This timeout is a leftover from the days of tdb, which didn't work well
and caused udev processes to spin around in a corrupted database.
I generally don't like to introduce more facy options to udev and better
set the alarm timeout to a reasonable default or remove it at all.
The problem occurs only on bootup running udevstart, right?
(Depending on your setup 'UDEV_RUN=0 /sbin/udevstart' may be a good
option to speed up the initial population of /dev. Don't know it you
really need to have RUN at that time, depends on how udev is integrated.)
Kay
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next prev parent reply other threads:[~2005-10-19 18:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-10-19 8:39 Udev incompatibility with qemu and bochs Alexander E. Patrakov
2005-10-19 17:45 ` Greg KH
2005-10-19 18:05 ` Kay Sievers [this message]
2005-10-20 1:45 ` Alexander E. Patrakov
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