Re: A few questions and issues with dynticks, NOHZ and powertop

From: Dominik Brodowski
Date: Sun Apr 04 2010 - 06:35:49 EST

Hi Dmitry,

On Sat, Apr 03, 2010 at 04:53:26PM -0700, Dmitry Torokhov wrote:
> On Sun, Apr 04, 2010 at 12:33:28AM +0200, Dominik Brodowski wrote:
> >
> > 4) SynPS/2 touchpad:
> > Why does moving the touchpad lead to sooo many IRQs? I can't look as fast
> > as the mouse pointer seems to get new data:
> > 62,5% (473,1) <interrupt> : PS/2 keyboard/mouse/touchpad
> >
> 80 pps @ 6 bytes/packet = 480 interrupts/sec.
> You can try using psmouse.rate=40 to limit it to 40 pps which should
> bring it to the rate of standard PS/2 mouse at the expense of
> sensitivity...

Excellent. Maybe this could be added to the Tips&Tricks section at the
Powertop website?

I guess obtaining all 6 bytes at once is not really possible? It
seems a new byte only appears ~1.75 ms after the last one, at least on my
notebook, so waiting for this is not an option...


PS: Dmitry, got something small for you in return:

[PATCH] i8042: spelling fix

Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 9302ba0..f61233e 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -38,7 +38,7 @@ MODULE_PARM_DESC(noaux, "Do not probe or use AUX (mouse) port.");

static bool i8042_nomux;
module_param_named(nomux, i8042_nomux, bool, 0);
-MODULE_PARM_DESC(nomux, "Do not check whether an active multiplexing conrtoller is present.");
+MODULE_PARM_DESC(nomux, "Do not check whether an active multiplexing controller is present.");

static bool i8042_unlock;
module_param_named(unlock, i8042_unlock, bool, 0);
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at