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diff --git a/README.md b/README.md new file mode 100644 index 000000000000..91af7cbf50be --- /dev/null +++ b/README.md @@ -0,0 +1,56 @@ +# linux-raspberrypi4-cacule-PKGBUILD + +## PKGBUILD for archlinuxarm with the cacule schedeuler. + +So far no perfomance/improvements tests done. Should work with desktop usage with a much better responsivty. +On x86_64 its one of the best schedeulers i have ever used. + +The patch can be applied for armv7 and armv8. You can use Cacule and Cacule-RDB. Cacule-RDB is still a expermintal thing. + +## Informations to Cacule-RDB + +This is an experimental load balancer for Cachy/CacULE. It is a lightweight +load balancer which is a replacement of CFS load balancer. It migrates +tasks based on their HRRN/Interactivity Scores (IS). Most of CFS load balancing-related +updates (cfs and se updates loads) are removed. The RDB balancer follows CFS +paradigm in which RDB balancing happen at the same points CFS does. RDB balancing happens +in three functions: newidle_balance, idle_balance, and active_balance. The newidle_balance +is called exactly at the same time as CFS did (when pick next task fails to find any task to run). +The RDB newidle_balance pulls one task that is the highest HRRN/IS from any CPU. The RDB idle_balance +is called in trigger_load_balance when CPU is idle, it does the same as newidle_balance but with +slight changes since newidle_balance is a special case. The RDB active_balance checks if the current +(NORMAL) runqueue has one task, if so, it pulls the highest of the highest HRRN/IS among all other CPUS. If the +runqueue has more than one task, then it pulls any highest HRRN/IS (same as idle does). A CPU cannot pull a task +from another CPU that has fewer tasks (when pull any). For the all three balancing +newidle_balance, idle_balance, and active_balance, the cpu first tries to pull from a CPU that shares the same +cache (cpus_share_cache). If can't pull any then it tries to pull from any CPU even though they are not in the same core. +Only when pulling the highest of the highest HRRN/IS (i.e. active_balance when CPU has one task), there is no check for +shared cache. + +Since trigger_load_balance is called for every tick, there is a guard time to prevent frequent tasks migration to reduce +runqueues locking and to reduce unnecessary tasks migrations. The time is 3ms after each active_balance. This time +guard is specifically for HZ=5 +0,1000. We don't want to run balancing every 2ms or 1ms to prevent regression in performance. +Here is how frequent the trigger_load_balance would run balancer with given HZ values: + +- HZ=100 runs every ~10ms +- HZ=250 runs every ~4ms +- HZ=300 runs every ~3ms +- HZ=500 runs every ~4ms +- HZ=1000 runs every ~3ms + + +### How to compile it + + git clone https://github.com/ptr1337/linux-raspberrypi4-cacule.git + cd linux-raspberrypi4-cacule + Then remove in the PKGBUILD if building for ***aarch64*** the 32-bit-converter.patch also the md5 + If you decide to use it without the RDB you need to remove in the config CONFIG_CACULE_RDB=y + then compile it with makepkg -si + + +reboot your device. + +## Cacule Schedeuler Informations + +https://github.com/hamadmarri/cacule-cpu-scheduler |