Just in case someone is still wondering why we are constantly talking about lowlatency kernel patches... Playing an mp3s with ecaplay, running as root with sched_fifo scheduling, disk i/o done in a separate i/o thread, smp-machine (usually helps to keep latency-peaks down), minor system load, I sometimes get the following stats:
(audioio-alsa3) warning! playback underrun - samples lost! Break was at least 8.76 ms long. (audioio-alsa3) warning! playback underrun - samples lost! Break was at least 1454.97 ms long. (audioio-alsa3) warning! playback underrun - samples lost! Break was at least 2347.27 ms long. (audioio-alsa3) warning! playback underrun - samples lost! Break was at least 931.64 ms long. Engine loop: Fastest/slowest/average loop time: 0.4/2364.1/5.9 msec. Disk i/o loop: Fastest/slowest/average loop time: 0.0/3930.2/0.5 msec. Just compare the avg and max values! This really is quite amazing - especially with the usually rock-solid sched-fifo+smp combination. PS Kernel is standard, non-patched linus-release. Sound driver is ALSA 0.9b8 (native-iface). -- http://www.eca.cx Audio software for Linux!
