Sony CR21/Z laptop (Latency problems related to ACPI?)

Sony CR21/Z laptop (Latency problems related to ACPI?)

[Panagiotis Papadakos]

Hello.

I have been using a cr21/z laptop which probably has
acpi related problems that introduce latency. I noticed
it because a recent update in my Ubuntu precise
makes my system's clock stay behind, and freezes
my laptop when there are no mouse or keyboard actions.

Somehow it looks related to https://bugzilla.kernel.org/show_bug.cgi?id=20172
 
If I boot my kernel with noapictimer clocksource=jiffies irqpoll
options the system reacts to my actions instantly. It is the first
time that I have exprerience lag free reactions from my system.
Unfortunately there are spikes of 100% CPU usage, due to irq polling I assume,
which makes my system less power efficient.

Is there any case that we can somehow fix this problem?

I am using latest git kernel. The same problem also exists
in current Ubuntu precise 3.2 kernel.

Thank you in advance.

Panagiotis Papadakos

Re: Sony CR21/Z laptop (Latency problems related to ACPI?)

[Panagiotis Papadakos]

Well, it seems that I only need noapic in my kernel options.
Also I guess this is a motherboard or BIOS bug right?

Thanks in advance.

On Monday 23 of April 2012 15:18:48 Panagiotis Papadakos wrote:
> Hello.
> 
> I have been using a cr21/z laptop which probably has
> acpi related problems that introduce latency. I noticed
> it because a recent update in my Ubuntu precise
> makes my system's clock stay behind, and freezes
> my laptop when there are no mouse or keyboard actions.
> 
> Somehow it looks related to
> https://bugzilla.kernel.org/show_bug.cgi?id=20172
> 
> If I boot my kernel with noapictimer clocksource=jiffies irqpoll
> options the system reacts to my actions instantly. It is the first
> time that I have exprerience lag free reactions from my system.
> Unfortunately there are spikes of 100% CPU usage, due to irq polling I
> assume, which makes my system less power efficient.
> 
> Is there any case that we can somehow fix this problem?
> 
> I am using latest git kernel. The same problem also exists
> in current Ubuntu precise 3.2 kernel.
> 
> Thank you in advance.
> 
> Panagiotis Papadakos