Hi, On Sat, 11 Aug 2007, Ingo Molnar wrote:
> the only relevant thing that comes to mind at the moment is that last > week Peter noticed a buggy aspect of sleeper bonuses (in that we do not > rate-limit their output, hence we 'waste' them instead of redistributing > them), and i've got the small patch below in my queue to fix that - > could you give it a try? It doesn't make much of a difference. OTOH if I disabled the sleeper code completely in __update_curr(), I get this: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3139 roman 20 0 1796 344 256 R 21.7 0.3 0:02.68 lt 3138 roman 20 0 1796 344 256 R 21.7 0.3 0:02.68 lt 3137 roman 20 0 1796 520 432 R 21.7 0.4 0:02.68 lt 3136 roman 20 0 1532 268 216 R 34.5 0.2 0:06.82 l Disabling this code completely via sched_features makes only a minor difference: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3139 roman 20 0 1796 344 256 R 20.4 0.3 0:09.94 lt 3138 roman 20 0 1796 344 256 R 20.4 0.3 0:09.94 lt 3137 roman 20 0 1796 520 432 R 20.4 0.4 0:09.94 lt 3136 roman 20 0 1532 268 216 R 39.1 0.2 0:19.20 l > this is just a blind stab into the dark - i couldnt see any real impact > from that patch in various workloads (and it's not upstream yet), so it > might not make a big difference. Can we please skip to the point, where you try to explain the intention a little more? If I had to guess that this is supposed to keep the runtime balance, then it would be better to use wait_runtime to adjust fair_clock, from where it would be evenly distributed to all tasks (but this had to be done during enqueue and dequeue). OTOH this also had then a consequence for the wait queue, as fair_clock is used to calculate fair_key. IMHO current wait_runtime should have some influence in calculating the sleep bonus, so that wait_runtime doesn't constantly overflow for tasks which only run occasionally. bye, Roman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
