Hi folks, I benchmarked Ingo's lowlatency-2.4.0-test7-A0 kernel (http://people.redhat.com/mingo/lowlatency-patches/lowlatency-2.4.0-test7-A0) I can only say that it looks VERY promising ( < 1msec latencies !) But there seems to be problems with the kernel disk sync code: After the disk stress test, I call the "sync" command, but unfortunately the sync process hangs and eats 100% of the CPU (but no kernel crash) see the graph here: http://www.linuxdj.com/latency/2.4.0-test7-lowlatency-A0/2048.html (disk copy and disk read tests are missing because, of the hanging sync) Is this perhaps related to the truncate bug fixed in -test8 ? Ingo, any ideas what the cause of the hang could be ? (let us know please when you port the patch to test8) Anyway if the remaining bugs can be fixed, then I think that that all low latency needs of 2.4 users will be satisfied. (my reference mark is being able to stay below 1.5 - 2msec, which is needed for perceptually delayfree realtime audio processing) PS: looking at the results Chris posted, http://cygnus.ipal.org/results-2.4.0t8-ll/3x256.html Andrew's minimalistic approach looks promising too and seems to be able to guarantee <5msec latencies under high load. cheers, Benno.
