Re: Keyboard Stuttering

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On Tue, 2006-10-10 at 13:09 -0400, Dmitry Torokhov wrote:
> On 10/6/06, David Gerber <[email protected]> wrote:
> > > I'm experiencing some severe keyboard stuttering on my laptop.  The
> > > problem is particularly bad in X, and I believe it also occurs at the
> > > console, though I'm having a difficult time verifying that.  The problem
> > > shows up as repeated characters (not regular key-repeat-related), and
> > > sometimes dropped key presses.
> >
> > (I'm not subscribed to the list, CC: to me if needed)
> >
> > Same problem here. Intel Core 2 Duo with 2.6.19-rc1 x86_64 SMP. Happens on
> > 2.6.17 too. I use 'noapic' as a workaround but that disables one of the CPU
> > core of course.
> >
> > I cannot reproduce the problem within the console nor gdm. Only on the X
> > desktop.
> >
> John,
> It looks like the only clocksource available on David's box is
> "jiffies" although the processor shows that it supporst tsc and PM
> timer is enabled and I think that this is what causes keyboard
> stuttering in X. See
> I believe clocksources is your turf, could you please take a look at
> this.

Sure thing. I followed up in the bug, but I don't think the clocksource
code is involved. x86_64 hasn't converted to GENERIC_TIME, so jiffies is
what we use to increment xtime, but the TSC, ACPI PM, or HPET is used
for gettimeofday, etc. 

I suspect C3 idling is the culprit, since noapic works around the issue.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at
Please read the FAQ at

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux