[fedora-arm] A 64 bit ARMv8 Android tablet arrives ...

[Andy Green]

On 17 October 2014 17:28:03 GMT+08:00, Peter Robinson <pbrobinson at gmail.com> wrote:
>>> >> The Non-US version of the Samsung Glaxy Note4 is powered by the
>>> >> Exynos7, which is an Octa Core A57/A53 in big.LITTLE config.
>>>
>>> Note4 with Qualcomm cpu is not US only device. So if you want to buy
>it
>>> with Exynos7 you have to check exactly what you buy.
>>>
>>> > I have mixed feelings about big.LITTLE based on my experience with
>the
>>> > (older, 32 bit) 5410.
>>>
>>> IIRC 5410 had wrong implementation of big.LITTLE or atleast
>incompatible
>>> with what came in all other cpus.
>>
>> .. and is rumoured to be broken (caching bugs) although I've
>> not experienced anything on mine.
>
>We currently don't support any form of little.BIG in Fedora. Until
>recently the only SoCs that supported it were exynos based and their
>support for multiprocessor kernels was terrible let alone some of
>their more exotic features. There are now other devices out there with
>the technology and dev boards with it on board but again most of that
>support isn't upstream, eg AllWinner A80 basic support isn't upstream
>yet.
>
>The other SoC with similar technology is Tegra and while their
>upstream support overall is generally very good there doesn't appear
>to be any drivers etc for scaling between their single companion core
>and the rest.
>
>While the technology is cute it is very much designed for the mobile
>phone/tablet market to save battery when in the pocket but to have
>enough power to play/record hi def video and hence in the short term I
>don't believe it really fits our use case and hence I've not spent

Not specifically about exynos, but it does make some difference about thermal behaviour which affects performance by limiting cpufreq if it gets hot, so it's not just a sideshow if your device is fanless.

-Andy

>much more time than the occasional cursory glance to see if it's any
>less broken. Besides, after a couple of months, I'm yet to get any
>positive confirmation that people are actually able to use our kernel
>with any Exynos based device.
>
>Peter
>_______________________________________________
>arm mailing list
>arm at lists.fedoraproject.org
>https://admin.fedoraproject.org/mailman/listinfo/arm