Re: System slow down from udev

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, May 29, 2013 at 02:30:12AM +0200, Rafael J. Wysocki wrote:
> On Tuesday, May 28, 2013 05:01:41 PM Yinghai Lu wrote:
> > On Tue, May 28, 2013 at 4:57 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > > On Tuesday, May 28, 2013 04:46:30 PM Yinghai Lu wrote:
> > >> On Tue, May 28, 2013 at 4:50 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > >> > On Tuesday, May 28, 2013 04:39:37 PM Yinghai Lu wrote:
> > >> >> Raphael:
> > >> >>
> > >> >> Found one commit in your linus-pm cause user space very slow...
> > >> >> at least from udev start...
> > >> >
> > >> > I obviously can't reproduce it, so it would be great if you could give me
> > >> > more details.
> > >> >
> > >> > Is there anything unusual about your test system?
> > >>
> > >> they are normal nehalem ex, westmere ex and ivybridge ex 8 sockets system.
> > >
> > > Do all of them have the same problem?
> > 
> > yes
> > 
> > >
> > > What distro is running there?
> > 
> > Using rescue initrd/root disk from opensuse 11.4 (?) and boot from network.
> > 
> > udevd version is 128.
> 
> I'm successfully running kernels including that commit on two different boxes
> (dual-core and quad-core, both Intel, the quad-core one is Sandy Bridge) with
> OpenSUSE 12.2 and 12.3.
> 
> There's a machine with an older OpenSUSE on it somewhere here, but I won't be
> able to get to it before tomorrow evening.
> 
> I have no idea what's wrong at the moment.
> 
> Please attach your .config for comparison and maybe Greg will have an idea about what's up with udev vs that commit (Greg, the
> commit in question, unfortunately far from trivial, is http://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=acpi-hotplug&id=ac212b6980d8d5eda705864fc5a8ecddc6d6eacc).

I don't see how this would "slow down" the boot process.  Can someone
run the bootchart tool on the machine to see where the delays are?

thanks,

greg k-h