Messages in this thread | | | Subject | Re: [RFC PATCH v2 0/2] sched: Nominate a power-efficient ILB | From | Suresh Siddha <> | Date | Tue, 21 Apr 2009 18:05:22 -0700 |
| |
On Mon, 2009-04-13 at 21:55 -0700, Gautham R Shenoy wrote: > Now, the other power-savings settings such as the sched_mc/smt_power_savings > and the power-aware IRQ balancer try to balance tasks/IRQs by taking > the system topology into consideration, with the intention of keeping > as many "power-domains" (cores/packages) in the low-power state. > > The current idle-load-balancer nomination does not necessarily align towards > this policy. For eg, we could be having tasks and interrupts largely running > on the first package with the intention of keeping the second package idle. > Hence, CPU 0 may be busy. The first_cpu in the nohz.cpu_mask happens to be CPU1, > which in-turn becomes nominated as the idle-load balancer. CPU1 being from > the 2nd package, would in turn prevent the 2nd package from going into a > deeper sleep state. > > Instead the role of the idle-load balancer could have been assumed by an > idle CPU from the first package, thereby helping the second package go > completely idle.
Can we also do this by default? i.e., even when no power-savings policy is selected.
I don't see anything wrong by enabling this logic for all the cases.
thanks, suresh
| |