| Subject | Re: [RFC PATCH 14/14] sched: implement usage tracking | From | Peter Zijlstra <> | Date | Thu, 16 Feb 2012 17:58:30 +0100 |
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On Wed, 2012-02-01 at 17:38 -0800, Paul Turner wrote: > struct sched_avg { > u64 runnable_avg_sum, runnable_avg_period; > u64 last_runnable_update, decay_count; > + u32 usage_avg_sum;
4 byte hole
> unsigned long load_avg_contrib; > > int contributes_blocked_load; >};
A) Running/Runnable - uses last_runnable_update to track runnable_avg_sum, usage_avg_sum and runnable_avg_period
B) Blocked - uses decay_count to keep track of sleeptime
C) 'Migrate' - uses contributes_blocked_load to check if we actually did migrate?
So there's a number of things I don't get, why have remove_task_load_avg_async() in set_task_rq()? enqueue_entity_load_avg() can do the __synchronize_entity_decay() thing (and actually does) just fine, right?
Similarly, why not use last_runnable_update (as last_update) to track both A and B since a task cannot be in both states at the same time anyway. If you always update the timestamp you can use it to either track runnable/usage or decay for sleep.
That would get rid of decay_count and contributes_blocked_load, no?
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