Messages in this thread | | | Date | Mon, 24 Jun 2013 20:11:02 -0400 | From | Steven Rostedt <> | Subject | Re: RFC: Allow block drivers to poll for I/O instead of sleeping |
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On Mon, Jun 24, 2013 at 09:17:18AM +0200, Jens Axboe wrote: > On Sun, Jun 23 2013, Linus Torvalds wrote: > > > > You could try to do that either *in* the idle thread (which would take > > the context switch overhead - maybe negating some of the advantages), > > or alternatively hook into the scheduler idle logic before actually > > doing the switch. > > It can't happen in the idle thread. If you need to take the context > switch, then you've negated pretty much all of the gain of the polled > approach.
What about hooking into the idle_balance code? That happens if we are about to go to idle but before the full schedule switch to the idle task.
In __schedule(void):
if (unlikely(!rq->nr_running)) idle_balance(cpu, rq);
-- Steve
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