Files
littlefs/benches/bench_helpers.c
T
Christopher Haster 7e307f2160 benches: Added bench_rbyd, bench_wt, and bench_helpers
These were copied from external benchmarks, and tweaked/simplified a
bit based on gained experience.

I mostly just wanted something to test the bench runner/scripts, with
bench_rbyd showcasing a low-level litmus benchmark, and bench_wt
showcasing a high-level throughput benchmark.

Though bench_wt has proven to be a _very_ versatile benchmark, and will
likely be the first stop for getting an understanding of high-level
performance implications.

---

Also added bench_helpers.h/c, which includes a couple helper functions:

- bench_helpers_warmup - Warm up the filesystem by writing a 1 block
  file 2*block_count times. This is meant to exhaust any preerased
  state, post-format lookahead buffers, etc.

- bench_helpers_usage - Find a tight bound on disk usage. This allocates
  a bitmap to find the tight bound, unlike lfs3_fs_usage, which is
  best-effort. However the bitmap is hidden behind BENCH_HEAP_PAUSE to
  prevent messing with parallel heap measurements.
2026-02-19 14:03:46 -06:00

96 lines
2.2 KiB
C

/*
* Some extra bench helpers
*
*/
#include "benches/bench_helpers.h"
// warm up the filesystem
//
// this writes a 1 block file 2*block_count times to get it into a good
// state for benchmarking
int bench_helpers_warmup(lfs3_t *lfs3) {
#ifdef BENCH_YES_STACK
BENCH_STACK_PAUSE();
#endif
#ifdef BENCH_YES_HEAP
BENCH_HEAP_PAUSE();
#endif
uint8_t *wbuf = malloc(BLOCK_SIZE);
memset(wbuf, '1', BLOCK_SIZE);
lfs3_file_t file;
lfs3_file_open(lfs3, &file, "warmup",
LFS3_O_WRONLY | LFS3_O_CREAT | LFS3_O_EXCL) => 0;
for (lfs3_block_t i = 0; i < 2*BLOCK_COUNT; i++) {
lfs3_file_rewind(lfs3, &file) => 0;
lfs3_file_write(lfs3, &file, wbuf, BLOCK_SIZE) => BLOCK_SIZE;
lfs3_file_sync(lfs3, &file) => 0;
}
lfs3_file_close(lfs3, &file) => 0;
lfs3_remove(lfs3, "warmup") => 0;
free(wbuf);
#ifdef BENCH_YES_HEAP
BENCH_HEAP_RESUME();
#endif
#ifdef BENCH_YES_STACK
BENCH_STACK_RESUME();
#endif
return 0;
}
// find tight disk usage
uintmax_t bench_helpers_usage(lfs3_t *lfs3) {
#ifdef BENCH_YES_STACK
BENCH_STACK_PAUSE();
#endif
#ifdef BENCH_YES_HEAP
BENCH_HEAP_PAUSE();
#endif
// measure disk usage
//
// littlefs can be a dag, so build a bitmap to find the exact
// disk usage
uint8_t *usage_bmap = malloc((BLOCK_COUNT+8-1)/8);
memset(usage_bmap, 0, (BLOCK_COUNT+8-1)/8);
lfs3_trv_t trv;
lfs3_trv_open(lfs3, &trv, 0) => 0;
while (true) {
struct lfs3_tinfo tinfo;
int err = lfs3_trv_read(lfs3, &trv, &tinfo);
assert(!err || err == LFS3_ERR_NOENT);
if (err == LFS3_ERR_NOENT) {
break;
}
usage_bmap[tinfo.block/8] |= 1 << (tinfo.block % 8);
}
lfs3_trv_close(lfs3, &trv) => 0;
lfs3_size_t usage = 0;
for (lfs3_size_t j = 0; j < BLOCK_COUNT; j++) {
if (usage_bmap[j / 8] & (1 << (j % 8))) {
usage += 1;
}
}
free(usage_bmap);
#ifdef BENCH_YES_HEAP
BENCH_HEAP_RESUME();
#endif
#ifdef BENCH_YES_STACK
BENCH_STACK_RESUME();
#endif
return (uintmax_t)usage * (uintmax_t)BLOCK_SIZE;
}