darethehair Posted June 27, 2017 Posted June 27, 2017 Not sure exactly where to post this, or how to ask it, but here goes... In the 'olden days' of my Linux adventures, compiling one's own kernel was standard practice. Thankfully, now many years later, I have become content with the 'standard' kernels (e.g. Debian) that are available to me on my x86 computers. Now, enter the world of ARM-based computing, and the possible return of self-compiled kernels. In my specific case, I am interested in using Pi-like devices to run a GPS-based time server with the additional accuracy of PPS. From my understanding, there are two optional-but-useful changes that would be required to maximal accuracy: - turning OFF the 'Tickless System' kernel option - modifying the 'pps-gpio' module for proper sensitivity to a GPS module 'PPS' pin I have found instructions for making these types of changes on an Armbian-based 'Orange Pi Plus' (which I am currently interested in), as well as other pages for 'Raspberry Pi' (most common). So here is my question: how *reasonable* is it to ask that the creators of the Armbian/DietPi/etc kernels make these changes 'standard' from now on in future kernels -- assuming that the general community would not care one way or the other? Is this a crazy thought?
zador.blood.stained Posted June 27, 2017 Posted June 27, 2017 19 minutes ago, darethehair said: - turning OFF the 'Tickless System' kernel option We are trying to keep the config balanced for different use cases (server, desktop, multimedia, IoT), and if a kernel option has a recommended value it would be best to use it. config NO_HZ_IDLE bool "Idle dynticks system (tickless idle)" depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select NO_HZ_COMMON help This option enables a tickless idle system: timer interrupts will only trigger on an as-needed basis when the system is idle. This is usually interesting for energy saving. Most of the time you want to say Y here. 19 minutes ago, darethehair said: - modifying the 'pps-gpio' module for proper sensitivity to a GPS module 'PPS' pin Usually if there is a patch foir the mainline kernel, then somebody needs to maintain this patch, adopting to kernel changes, otherwise this patch will be thrown out if it doesn't apply cleanly or breaks the compilation. 21 minutes ago, darethehair said: So here is my question: how *reasonable* is it to ask that the creators of the Armbian/DietPi/etc kernels make these changes 'standard' from now on in future kernels -- assuming that the general community would not care one way or the other? The most reasonable solution in my opinion for this rather unusual use case would be to compile the kernel with required changes and patches, put the kernel packages on hold and forget about it unless you require a newer kernel for some reason. 2
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