[BUG] 2.6.2 crazy mouse under heavy load

[BUG] 2.6.2 crazy mouse under heavy load

[Luis Miguel García]

 >  Compiling recent kde-3.2.0-final, on twm with xterm, several times 
the mouse is out of control!!!!


The same happened to me. I was thinking if the cause could be the 
batteries of my wireless mouse, but seeing your post, it could really be 
a bug.

Any way of reproduce it?

Any test to perform?

Thanks!

Luis Miguel Garcia

Re: [BUG] 2.6.2 crazy mouse under heavy load

[Murilo Pontes]

My mouse is not wireless, is a logitech ps/2 mouse whell
To reprocude is simple put heavy loader such compile a larger C++ source like kde-3.2


Em Qui 05 Fev 2004 17:34, você escreveu:
>  >  Compiling recent kde-3.2.0-final, on twm with xterm, several times 
> the mouse is out of control!!!!
> 
> 
> The same happened to me. I was thinking if the cause could be the 
> batteries of my wireless mouse, but seeing your post, it could really be 
> a bug.
> 
> Any way of reproduce it?
> 
> Any test to perform?
> 
> Thanks!
> 
> Luis Miguel Garcia
> 

Re: [BUG] 2.6.2 crazy mouse under heavy load

[Bob Gill]

The exception seems to be coming from
linux-2.6.2/drivers/input/mouse/psmouse-base.c, specifically from

if (psmouse->state == PSMOUSE_ACTIVATED &&
            psmouse->pktcnt && time_after(jiffies, psmouse->last +
HZ/2)) {
                printk(KERN_WARNING "psmouse.c: %s at %s lost
synchronization, throwing %d bytes away.\n",
                       psmouse->name, psmouse->phys, psmouse->pktcnt);
                psmouse->pktcnt = 0;
        }


where (for me) HZ is 1804768000, and therefore HZ/2 is 902384000,  
psmouse->pktcnt is 3, and (I assume) PSMOUSE_ACTIVATED is non-0 after
boot.  I assume that pktcnt is fed by interrupt, and the problem then is
that psmouse->last + HZ/2 blows past the jiffies value, causing the
warning message to be issued.  When mouse service finally comes back,
pktcnt is non-zero (and possibly whatever the maximum is that it will
hold), and when it flushes, the mouse pointer goes nuts for a second. 
The real problem then, is why does the sum of ps->last + HZ/2 grow to
beyond the size of jiffies (or what is delaying the mouse service)?

This is just a rough guesstimate of what is going on, but seems to fit
the facts.   Cheers!

Bob

Re: [BUG] 2.6.2 crazy mouse under heavy load

[Vojtech Pavlik]

On Thu, Feb 05, 2004 at 01:59:12PM -0700, Bob Gill wrote:
> The exception seems to be coming from
> linux-2.6.2/drivers/input/mouse/psmouse-base.c, specifically from
> 
> if (psmouse->state == PSMOUSE_ACTIVATED &&
>             psmouse->pktcnt && time_after(jiffies, psmouse->last +
> HZ/2)) {
>                 printk(KERN_WARNING "psmouse.c: %s at %s lost
> synchronization, throwing %d bytes away.\n",
>                        psmouse->name, psmouse->phys, psmouse->pktcnt);
>                 psmouse->pktcnt = 0;
>         }
> 
> 
> where (for me) HZ is 1804768000, and therefore HZ/2 is 902384000,  

This looks very wrong. HZ should be 1000 on a normal machine.
Maybe you were looking at jiffies?

> psmouse->pktcnt is 3, and (I assume) PSMOUSE_ACTIVATED is non-0 after
> boot.  I assume that pktcnt is fed by interrupt, and the problem then is
> that psmouse->last + HZ/2 blows past the jiffies value, causing the
> warning message to be issued.  When mouse service finally comes back,
> pktcnt is non-zero (and possibly whatever the maximum is that it will
> hold), and when it flushes, the mouse pointer goes nuts for a second. 
> The real problem then, is why does the sum of ps->last + HZ/2 grow to
> beyond the size of jiffies (or what is delaying the mouse service)?

Exactly. The if statement means "If no data arrived for more than half a
second, and we're in the middle of a packet, something is wrong - we
better should start from scratch."

The goal of that statement is to resynchronize the mouse data stream if
a byte is lost.

-----

There are two scenarios of this message appearing (assuming 4-byte
packets):

#1 Messages always appearing in pairs, and the sum being 4. This is a
delayed or lost interrupt. Since the driver polls the controller in
addition to servicing interrupts, if the controller has the byte,
regardless of whether an interrupt arrived, it'll be processed.

#2 Messages appearing single, with numbers from 1 to 3. This is a lost
byte. The controller either didn't receive the byte at all or something
very fishy happened.

> This is just a rough guesstimate of what is going on, but seems to fit
> the facts.   Cheers!
 

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR

re: [BUG] 2.6.2 crazy mouse under heavy load

[Luis Miguel García]

 >  Compiling recent kde-3.2.0-final, on twm with xterm, several times 
the mouse is out of control!!!!


The same happened to me. I was thinking if the cause could be the 
batteries of my wireless mouse, but seeing your post, it could really be 
a bug.

Any way of reproduce it?

Any test to perform?

Thanks!

Luis Miguel Garcia

[BUG] 2.6.2 crazy mouse under heavy load

[Murilo Pontes]

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Compiling recent kde-3.2.0-final, on twm with xterm, several times the mouse is out of control!!!!

-------Syslog output--------------
psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing 3 bytes away.
psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing 3 bytes away.
--------------------------------------

Any ideias?


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Re: [BUG] 2.6.2 crazy mouse under heavy load

[Norberto Bensa]

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Murilo Pontes wrote:
> Compiling recent kde-3.2.0-final, on twm with xterm, several times the
> mouse is out of control!!!!

2.6.2-rc3-mm1. Compiling same packages on Gentoo. When the box starts 
swapping, it is almost totally unresponsive.

> Any ideias?

Wait 'til developement on 2.6.x stabilize :-)

Regards,
Norberto

-- 
Linux 2.6.2-mm1 Pentium III (Coppermine) GenuineIntel GNU/Linux
 15:16:26 up 58 min,  2 users,  load average: 1.18, 1.92, 1.74

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Re: [BUG] 2.6.2 crazy mouse under heavy load

[Wichert Akkerman]

Previously Norberto Bensa wrote:
> 2.6.2-rc3-mm1. Compiling same packages on Gentoo. When the box starts 
> swapping, it is almost totally unresponsive.

I had the same happen to me with vanilla 2.6.2 yesterday, but I was
messing around with ndiswrappers at the time so it might be unrelated.

Wichert.

-- 
Wichert Akkerman <wichert@wiggy.net>    It is simple to make things.
http://www.wiggy.net/                   It is hard to make things simple.

Re: [BUG] 2.6.2 crazy mouse under heavy load

[hungerburg]

Murilo Pontes wrote:
> Compiling recent kde-3.2.0-final, on twm with xterm, several times the
> mouse is out of control!!!!

did you enable DMA on the disks?

hu

Re: [BUG] 2.6.2 crazy mouse under heavy load

[Harald Dunkel]

Murilo Pontes wrote:
> Compiling recent kde-3.2.0-final, on twm with xterm, several times the mouse is out of control!!!!
> 

Tried to disable CONFIG_PREEMPT? I kicked it out,
and my mouse never went mad since then. Surely
just a workaround (if it helps at all).


Good luck

Harri