Hey folks, I've run into two web sites that claim that the Linux kernel causes performance problems in particular games (see below). Anybody know of others?
And has anybody found concrete improvements in performance of a particular app (other than an audio workstation app) from using a realtime kernel?
Thanks! - Dan
First:
http://wiki.archlinux.org/index.php/World_of_Warcraft#Kernel_Timing_Bug says in a section dated September 2008: "If you are having problems with choppy video every 15 seconds or so, it is related to the kernel scheduler... to fix, add CONFIG_SCHED_DEBUG=y to your kernel config, then set kernel.sched_features=21 kernel.sched_batch_wakeup_granularity_ns=25000000 kernel.sched_min_granularity_ns=4000000 in /etc/sysctl.cfg."
Yikes. Any truth to that rumor?
Second:
http://hisouten.koumakan.jp/wiki/Linux_support#Resolved_bugs says
"The game runs too slowly Symptoms: Instead of running at about 60-62fps, like the game is supposed to, it'll run closer to 53fps. This is not ideal. The bug: This is a Linux timing issue. The game runs a secondary timing thread with THREAD_PRIORITY_TIME_CRITICAL, where it simply sleeps for 16ms and sends events to the main thread to tell it that a new frame is needed. On Linux the necessary timing accuracy is not available, so it wavers between 16ms and 20ms. The fix: I hacked around this by setting the timer period to 14ms. This leads to a steady 62-63fps. Which is close enough for use, really. For a constant 60fps turn on vsync in your video drivers."