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 ? > > Regards > Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
