huntedbytheirsandSisyphus
370e64c3a6
smoke links crt0.o + libc.a with -nostdlib -static and proves the whole chain runs without the dynamic linker; bench_strlen and bench_syscall measure the string core and raw syscall round-trip cost via make bench. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <[email protected]>
30 lines
703 B
C
30 lines
703 B
C
/*
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* bench_syscall.c — raw syscall round-trip cost.
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*
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* This is the number that justifies the whole project: for a kernel-first
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* libc (project guideline #6), every wrapper is one `syscall` instruction
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* away from the kernel. getpid() is the cheapest syscall there is, so
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* this measures the floor. 1M iterations; results in ns per call.
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*/
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#include <unistd.h>
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#include "bench.h"
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#define ITERS 1000000UL
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int main(void)
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{
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volatile pid_t sink = 0;
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long long t0, t1;
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t0 = bench_now_ns();
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for (unsigned long i = 0; i < ITERS; i++)
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sink += getpid();
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t1 = bench_now_ns();
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(void)sink;
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bench_print_u64((unsigned long long)((t1 - t0) / ITERS));
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return 0;
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}
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