hard-lock with CPU spinning
keramida at freebsd.org
Fri Jun 22 12:42:56 UTC 2007
On 2007-06-17 19:32, Giorgos Keramidas <keramida at freebsd.org> wrote:
>On 2007-06-14 20:02, Giorgos Keramidas <keramida at ceid.upatras.gr> wrote:
>>On 2007-06-14 18:36, Attilio Rao <attilio at freebsd.org> wrote:
>>>2007/6/14, Giorgos Keramidas <keramida at ceid.upatras.gr>:
>>>> If I leave my laptop idle for a long period of time, it tends to lock up
>>>> with the CPU fan spinning fast (presumambly because some part of the
>>>> kernel tries to acquire a lock and spins constantly for it).
>>>> Unfortunately, this happens when X11 is running and I can't break into
>>>> DDB to snoop around.
> Hi Attilio,
> thanks for the eagerness to help, but I was too quick in assuming this
> was a hard-lock. The kernel hasn't deadlocked, but the laptop is almost
> unresponsive because the X server eats up an enormous amount of CPU.
> I left an xterm window running:
> > cd /home/keramida
> > ( while true ; do \
> uptime ; ps xaur | head -20 ; \
> sleep 5 ; echo ; \
> done ) 2>&1 | tee logfile
> and when hte CPU fan started spinning fast, I managed to shutdown
> normally by pressing the laptop's power-off button and waiting long
> enough for the X process to die.
> The ~/logfile file contains near its end entries like:
> % 6:43PM up 2:05, 1 user, load averages: 0.76, 0.39, 0.24
> % USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
> % root 1234 97.8 4.2 285648 21428 v1 R 4:41PM 3:22.41 X :0 -dpi 96 (Xorg)
> % root 12 97.1 0.0 0 8 ?? RL 4:37PM 112:19.80 [idle: cpu0]
> % root 11 2.2 0.0 0 8 ?? RL 4:37PM 110:16.80 [idle: cpu1]
Finally, more progress :)
This seems to kick in only when I use:
% xset +dpms
% xset s on
% xset b 100 800 20
By disabling DPMS with '-dpms' there is no CPU-eating behavior
even after leaving my laptop on for hours.
So this seems to be a bug in the +dpms part of X11 :-)
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