Subject: Re: Keys get stuck
From: Mike Galbraith <efault@gmx.de>
To: Hans-Peter Jansen <hpj@urpla.net>
Cc: linux-kernel@vger.kernel.org, Jiri Kosina <jkosina@suse.cz>,
       David Newall <davidn@davidnewall.com>, Theodore Tso <tytso@mit.edu>,
       "Fred ." <eldmannen@gmail.com>
In-Reply-To: <200803122222.05663.hpj@urpla.net>
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	 <47D8091E.6030906@davidnewall.com>
	 <Pine.LNX.4.64.0803121748140.15209@jikos.suse.cz>
	 <200803122222.05663.hpj@urpla.net>
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Date: Thu, 13 Mar 2008 06:42:13 +0100
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On Wed, 2008-03-12 at 22:22 +0100, Hans-Peter Jansen wrote:
> Am Mittwoch, 12. März 2008 schrieb Jiri Kosina:
> > On Thu, 13 Mar 2008, David Newall wrote:
> > > > The problem is that under heavy load the auto-repeat problem is real;
> > > > I've seen it as well, and it means that I've started to try to avoid
> > > > "make -j4" since that's a great way to trigger it.
> > >
> > > I'm sure it does suck under heavy load, although I suppose you could
> > > increase the start time.  But I wonder if that is the problem this
> > > time?  Modern machines are so damned fast they actually take real
> > > effort to load.  Actually, "make -j4" doesn't sound particularly heavy.
> > > There's huge disk i/o in a make.  Plenty of scheduling opportunities.
> > > Obviously I only know what everybody else here knows; but with so many
> > > recent posts suggesting a scheduling fault has been introduced, I'm
> > > expecting it to be that.
> >
> > The problem became much more apparent during early -rc phase of 2.6.25
> > for those people that have CONFIG_GROUP_SCHED turned on. This clearly
> > shows that X are somehow unhappy with how kernel schedules them, but I
> > don't have idea how autorepeat is implemented inside X and what could be
> > the problem right now.
> 
> Just for the record, this problem started with openSUSE 10.2 for me, that's 
> a 2.6.18 thingy. I'm a heavy xterm user, where the autorepeat gets a life 
> of its own _occasionally_. I'm able to stop it by triggering a autorepeat 
> manually (typical antidot reaction).

I've seen these key repeats for years.  All I ever had to do was to make
X run heavily enough in the presence of another (hefty) load that it
hits the expired array and thereby takes a serious latency hit.  I
always considered key repeats under load to be X's quaint way of saying
"HEEEEELP MEEEE" ;-)

	-Mike

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