riscv64: Use Sstc extension to manage timer

[sbutz]

Implements #2702.

RISC-V Profile RVA23 mandates the Sstc extension.
IMHO using Sstc should be default. Qemu 'rv64' supports it too. Sifive U740 Freedom not.

Blocked by integration of hermit-os/hermit-rs#1086
Blocked by integration of rust-embedded/riscv#419

[github-actions]

Benchmark Results

Details

Benchmark	Current: 2b7a7cc	Previous: 2e23902	Performance Ratio
startup_benchmark Build Time	93.04 s	80.34 s	1.16 ❗
startup_benchmark File Size	0.79 MB	0.80 MB	0.99 ❗
Startup Time - 1 core	0.72 s (±0.02 s)	0.75 s (±0.02 s)	0.96 ❗
Startup Time - 2 cores	0.72 s (±0.02 s)	0.74 s (±0.02 s)	0.98
Startup Time - 4 cores	0.71 s (±0.02 s)	0.74 s (±0.02 s)	0.96 ❗
multithreaded_benchmark Build Time	94.72 s	82.11 s	1.15 ❗
multithreaded_benchmark File Size	0.88 MB	0.86 MB	1.02 ❗
Multithreaded Pi Efficiency - 2 Threads	67.11 % (±6.63 %)	85.89 % (±6.61 %)	0.78 ❗
Multithreaded Pi Efficiency - 4 Threads	41.32 % (±2.95 %)	43.43 % (±2.56 %)	0.95
Multithreaded Pi Efficiency - 8 Threads	19.54 % (±1.63 %)	25.76 % (±1.53 %)	0.76 ❗
micro_benchmarks Build Time	220.26 s	80.40 s	2.74 ❗
micro_benchmarks File Size	0.88 MB	0.86 MB	1.02 ❗
Scheduling time - 1 thread	165.03 ticks (±35.79 ticks)	62.65 ticks (±4.06 ticks)	2.63 ❗
Scheduling time - 2 threads	101.63 ticks (±22.17 ticks)	34.08 ticks (±4.10 ticks)	2.98 ❗
Micro - Time for syscall (getpid)	9.18 ticks (±5.34 ticks)	3.45 ticks (±0.58 ticks)	2.66 ❗
Memcpy speed - (built_in) block size 4096	58925.21 MByte/s (±41482.94 MByte/s)	82448.38 MByte/s (±56997.13 MByte/s)	0.71
Memcpy speed - (built_in) block size 1048576	14141.73 MByte/s (±11680.06 MByte/s)	30585.98 MByte/s (±24707.84 MByte/s)	0.46
Memcpy speed - (built_in) block size 16777216	11976.29 MByte/s (±9925.52 MByte/s)	26340.06 MByte/s (±21720.96 MByte/s)	0.45
Memset speed - (built_in) block size 4096	59261.74 MByte/s (±41740.86 MByte/s)	82292.76 MByte/s (±56891.50 MByte/s)	0.72
Memset speed - (built_in) block size 1048576	14477.33 MByte/s (±11847.64 MByte/s)	31323.85 MByte/s (±25145.86 MByte/s)	0.46
Memset speed - (built_in) block size 16777216	12240.07 MByte/s (±10067.66 MByte/s)	27104.68 MByte/s (±22209.94 MByte/s)	0.45
Memcpy speed - (rust) block size 4096	54370.77 MByte/s (±38760.31 MByte/s)	74097.96 MByte/s (±51811.44 MByte/s)	0.73
Memcpy speed - (rust) block size 1048576	14616.31 MByte/s (±12212.58 MByte/s)	30361.60 MByte/s (±24602.37 MByte/s)	0.48
Memcpy speed - (rust) block size 16777216	12564.86 MByte/s (±10853.01 MByte/s)	27625.34 MByte/s (±22806.88 MByte/s)	0.45
Memset speed - (rust) block size 4096	54885.73 MByte/s (±39161.32 MByte/s)	74373.47 MByte/s (±51976.48 MByte/s)	0.74
Memset speed - (rust) block size 1048576	15082.71 MByte/s (±12512.38 MByte/s)	31110.89 MByte/s (±25033.24 MByte/s)	0.48
Memset speed - (rust) block size 16777216	12970.43 MByte/s (±11132.05 MByte/s)	28386.93 MByte/s (±23265.03 MByte/s)	0.46
alloc_benchmarks Build Time	218.62 s	74.76 s	2.92 ❗
alloc_benchmarks File Size	0.87 MB	0.87 MB	0.99 ❗
Allocations - Allocation success	91.38 %	91.31 %	1.00 ❗
Allocations - Deallocation success	100.00 %	100.00 %	1
Allocations - Pre-fail Allocations	61.60 %	61.44 %	1.00 ❗
Allocations - Average Allocation time	27497.77 Ticks (±1795.90 Ticks)	5860.58 Ticks (±98.43 Ticks)	4.69 ❗
Allocations - Average Allocation time (no fail)	28598.42 Ticks (±2106.69 Ticks)	6554.81 Ticks (±92.86 Ticks)	4.36 ❗
Allocations - Average Deallocation time	8525.58 Ticks (±2375.81 Ticks)	1805.01 Ticks (±250.35 Ticks)	4.72 ❗
mutex_benchmark Build Time	216.51 s	79.82 s	2.71 ❗
mutex_benchmark File Size	0.88 MB	0.86 MB	1.02 ❗
Mutex Stress Test Average Time per Iteration - 1 Threads	33.70 ns (±7.01 ns)	12.10 ns (±0.41 ns)	2.79 ❗
Mutex Stress Test Average Time per Iteration - 2 Threads	30.10 ns (±8.29 ns)	40.26 ns (±1.68 ns)	0.75 ❗

This comment was automatically generated by workflow using github-action-benchmark.