Re: [patch] CFS scheduler, -v12

["Dmitry Adamushko" <dmitry.adamushko@gmail.com>]

On 18/05/07, Peter Williams <pwil3058@bigpond.net.au> wrote:
> [...]
> One thing that might work is to jitter the load balancing interval a
> bit.  The reason I say this is that one of the characteristics of top
> and gkrellm is that they run at a more or less constant interval (and,
> in this case, X would also be following this pattern as it's doing
> screen updates for top and gkrellm) and this means that it's possible
> for the load balancing interval to synchronize with their intervals
> which in turn causes the observed problem.  A jittered load balancing
> interval should break the synchronization.  This would certainly be
> simpler than trying to change the move_task() logic for selecting which
> tasks to move.

Just an(quick) another idea. Say, the load balancer would consider not
only p->load_weight but also something like Tw(task) =
(time_spent_on_runqueue / total_task's_runtime) * some_scale_constant
as an additional "load" component (OTOH, when a task starts, it takes
some time for this parameter to become meaningful). I guess, it could
address the scenarios your have described (but maybe break some others
as well :) ...
Any hints on why it's stupid?


>
> Peter
> --
> Peter Williams                                   pwil3058@bigpond.net.au

-- 
Best regards,
Dmitry Adamushko