Re: [v2 PATCH 0/4] timers: framework for migration between CPU

From: Ingo Molnar
Date: Wed Mar 04 2009 - 12:34:10 EST



* Arun R Bharadwaj <arun@xxxxxxxxxxxxxxxxxx> wrote:

> $taskset -c 4,5,6,7 make -j4
>
> my_driver queuing timers continuously on CPU 10.
>
> idle load balancer currently on CPU 15
>
>
> Case1: Without timer migration Case2: With timer migration
>
> -------------------- --------------------
> | Core | LOC Count | | Core | LOC Count |
> | 4 | 2504 | | 4 | 2503 |
> | 5 | 2502 | | 5 | 2503 |
> | 6 | 2502 | | 6 | 2502 |
> | 7 | 2498 | | 7 | 2500 |
> | 10 | 2501 | | 10 | 35 |
> | 15 | 2501 | | 15 | 2501 |
> -------------------- --------------------
>
> --------------------- --------------------
> | Core | Sleep time | | Core | Sleep time |
> | 4 | 0.47168 | | 4 | 0.49601 |
> | 5 | 0.44301 | | 5 | 0.37153 |
> | 6 | 0.38979 | | 6 | 0.51286 |
> | 7 | 0.42829 | | 7 | 0.49635 |
> | 10 | 9.86652 | | 10 | 10.04216 |
> | 15 | 0.43048 | | 15 | 0.49056 |
> --------------------- ---------------------
>
> Here, all the timers queued by the driver on CPU10 are moved to CPU15,
> which is the idle load balancer.

The numbers with this automatic method based on the ilb-cpu look
pretty convincing. Is this what you expected it to be?

Ingo
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