Re: [patch 00/22] high resolution timers / dynamic ticks - V3

[Ingo Molnar <mingo@elte.hu>]

* Andrew Morton <akpm@osdl.org> wrote:

> With CONFIG_HIGH_RES_TIMERS=y, CONFIG_NO_HZ=n it's pretty sick.  It 
> pauses for several seconds after "input: AlpsPS/2 ALPS GlidePoint as 
> /class/input/input2" (printk-time claims 2 seconds, but it was longer 
> than that).
> 
> It's been stuck for a minute or more at the 12.980000 time, seems to 
> have hung.  The cursor is flashing extremely slowly.

ah, that's still the VAIO, right? Do you get a 'slow' LOC count on 
/proc/interrupts even on a stock kernel? If yes then that's a 
fundamentally sick local APIC timer interrupt. Stock kernel should show 
sickness too, if for example you boot an SMP kernel on it - can you 
confirm that? (the UP-IOAPIC only relies for profiling on the lapic 
timer, so there the only sickness you should see on the stock kernel is 
a non-working readprofile)

We'll figure out a way to detect this hardware sickness (which is 
unrelated to our patchset), for now your workaround is either to turn 
off local-apic-timer support (either in the config or on the kernel 
bootline, in which case the high-res code will fall back to the PIT), or 
to turn off high-res timers (either in the config or on the kernel 
bootline).

	Ingo