On Mon, Jul 9, 2012 at 8:40 PM, Vincent Guittot <vincent.guit...@linaro.org> wrote: > On 9 July 2012 16:37, Shilimkar, Santosh <santosh.shilim...@ti.com> wrote: >> On Mon, Jul 9, 2012 at 8:06 PM, Vincent Guittot >> <vincent.guit...@linaro.org> wrote: >>> On 9 July 2012 15:00, Shilimkar, Santosh <santosh.shilim...@ti.com> wrote: >>>> On Mon, Jul 9, 2012 at 6:02 PM, Vincent Guittot >>>> <vincent.guit...@linaro.org> wrote: >>>>> On 9 July 2012 12:55, Shilimkar, Santosh <santosh.shilim...@ti.com> wrote: >>>>>> Vincent, >>>>>> On Mon, Jul 9, 2012 at 2:57 PM, Vincent Guittot >>>>>> <vincent.guit...@linaro.org> wrote: >>>>>>> Use cpu compatibility field and clock-frequency field of DT to >>>>>>> estimate the capacity of each core of the system and to update >>>>>>> the cpu_power field accordingly. >>>>>>> This patch enables to put more running tasks on big cores than >>>>>>> on LITTLE ones. But this patch doesn't ensure that long running >>>>>>> tasks will run on big cores and short ones on LITTLE cores. >>>>>>> >>>>>>> Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org> >>>>>>> Reviewed-by: Namhyung Kim <namhy...@kernel.org> >>>>>>> --- >>>>>>> arch/arm/kernel/topology.c | 153 >>>>>>> ++++++++++++++++++++++++++++++++++++++++++++ >>>>>>> 1 file changed, 153 insertions(+) >>>>>>> >>>>>> Sorry for not giving this comment on previous version but we should also >>>>>> have a way to provide the big.LITTLE information without Device Tree. >>>>>> May be a platform device/data. >>>>> >>>>> Hi Santosh, >>>>> >>>>> I had thought of adding such additional way to set cpu_power of >>>>> big.LITTLE but my conclusion was >>>>> -it's a new platform so it should come with DT >>>>> -DT is already required by other patches linked to big.LITTLE >>>>> (http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/080873.html) >>>>> -There is no device that can be easily used to get such information at >>>>> this early boot stage. >>>>> >>>> I see. Its new processor but it is just 1 one of the IP in an entire SOC. >>>> As mentioned below I was talking about full SOC support including >>>> all the driver subsystem with DT. >>>> >>>>>> >>>>>> I know we are moving DT way, but remember apart from core kernel >>>>>> infrastructure, to have a complete product build with DT means all the >>>>>> drivers must be already supporting DT which is not the case with >>>>>> many huge driver sub-systems like USB, display subsystem, Audio etc. >>>>>> >>>>>> Having that support would greatly help for the SOC's which have not yet >>>>>> reached to stage where entire SOC is DT compliant and want to use >>>>>> big.LITTLE infrastructure. >>>>> >>>>> Can't you support both type of devices on your platform ? You can move >>>>> your device to DT mode when it is supported ? >>>>> >>>> That is what eventually people end up doing who don't have >>>> DT ready for entire SOC. I was trying to ask whether at least some >>>> method is proposed(need not be merged in mainline) to have >>>> the big.LITTLE information parsing without DT. >>> >>> Ok, IIUC, you need a temporary methods, which doesn't need to be >>> merged in mainline, to set the cpu_scale field ? >>> >> Yep. > > You could use set_power_scale in your platform code to set the > cpu_power of your CPUs until DT is ready for your platform. > Thanks for the clarification. Will try that out.
Regards Santosh _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
