1 Topic by genail

  • genail
  • New member
  • Offline

Topic: sched_yield() on OpenSUSE and game pauses

Hello,

I've noticed a strange behavior with the game on OpenSUSE 11.1. Previously I had Debian sid/lenny and everything was ok...

When I'll run Teeworlds 0.5.1 and join a game it's everything all right. Problem starts when I'll disconnect and join other (or the same) server. The game pauses for a 2/5 or 3/5 of a second in random moments.

I've made a research that tells me that other process in system can make the pause. This is the result of strace -c -f when everything is working fine:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 28.25    9.580599     4790300         2         1 waitpid
 26.55    9.006770        1286      7005           nanosleep
 24.97    8.469265         169     50086         1 futex
 19.47    6.603668         103     64045           poll
  0.25    0.085541           0   2208483           sched_yield
  0.25    0.084557          19      4493         1 ioctl
  0.13    0.043542           0    458162           gettimeofday

And when I join another game:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 30.37 1424.512992        4858    293210         4 futex
 29.88 1401.628879         104  13494042           sched_yield
 24.00 1125.832191         380   2966590           gettimeofday
 23.77 1115.024835       19199     58076           write
 20.55  963.705104       21199     45459           nanosleep
 15.85  743.617462        2834    262435    160246 read
 15.10  708.214086       19201     36884     25191 recvfrom
 12.96  607.998292       20293     29961         1 ioctl

Look at sched_yield() system call in both examples.

I was watching at the "top" while playing game and nothing suspicious was going on there.
Btw. I have some sound clicks and pops problems too, but not only in Teeworlds. This is related to PulseAudio so this is my first suspect.

2 Reply by genail

  • genail
  • New member
  • Offline

Re: sched_yield() on OpenSUSE and game pauses

Ok sched_yield is good. I've made little source hacking and this is not a direct problem. There are also a few more system calls that can be the problem. PulseAudio is good too.

Oh and yeah... I've have a NVIDIA 9600 graphics card and I've noticed that when glxgears and teeworlds are running in the same time then both things freezes in the same moment. Other parts of the system are running fine. Maybe the graphics driver? But why I must join a game twice to see that issue? I'll try older drivers later.