Messages in this thread | | | Date | Mon, 18 Nov 2002 00:18:54 -0800 | From | William Lee Irwin III <> | Subject | unusual scheduling performance |
| |
On 16x, 2.5.47 kernel compiles take about 26s when the machine is otherwise idle.
On 32x, 2.5.47 kernel compiles take about 48s when the machine is otherwise idle.
When a single-threaded task consumes an entire cpu, kernel compiles take 36s on 32s when the machine is idle aside from the task consuming that cpu and the kernel compile itself.
I suspect the scheduler, because cpu reporting in top(1) shows that a two or more cpu-intensive tasks are concentrated on the same cpu, and some long-lived tasks appear to be "bouncing" across cpus. If someone with knowledge and/or expertise with respect to scheduling semantics could look into this, I would be much obliged. Resolving this would likely address many SMP and/or NUMA scheduling performance issues.
Thanks, Bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |