Function cbm_mem_rss

src/foundation/mem.c:437–470

}

size_t cbm_mem_rss(void) {
#if defined(__linux__)
    /* Linux: mimalloc's _mi_prim_process_info() (vendored/mimalloc/src/prim/
     * unix/prim.c) never sets pinfo->current_rss on Linux — it only sets
     * peak_rss (from getrusage's ru_maxrss). current_rss therefore keeps
     * mi_process_info()'s default of pinfo.current_commit: mimalloc's OWN
     * committed-page counter, which this project deliberately tunes low via
     * mi_option_arena_eager_commit=0 + purge_decommits=1 + purge_delay=0
     * (cbm_mem_init) to reduce upfront memory. So on Linux "current_rss" is a
     * low-biased mimalloc-internal metric, not true RSS: under concurrent
     * large-file parsing it can read a few MB while real RSS is multiple GB,
     * silently blinding cbm_mem_over_budget()'s backpressure to real memory
     * pressure (small-but-nonzero, so the `current_rss > 0` guard below never
     * catches it). os_rss() reads /proc/self/statm — authoritative OS RSS,
     * unaffected by mimalloc's accounting — so it is the PRIMARY source on
     * Linux, not a last-resort fallback. macOS/Windows are unaffected:
     * mimalloc sets current_rss correctly there via task_info /
     * GetProcessMemoryInfo. */
    size_t proc_rss = os_rss();
    if (proc_rss > 0) {
        return proc_rss;
    }
    /* Extremely unlikely (/proc unavailable) — fall through to mimalloc. */
#endif
    size_t current_rss = 0;
    size_t peak_rss = 0;
    mi_process_info(NULL, NULL, NULL, &current_rss, &peak_rss, NULL, NULL, NULL);
    if (current_rss > 0) {
        return current_rss;
    }
    /* Fallback for ASan builds (MI_OVERRIDE=0) and any platform where
     * mimalloc's current_rss is unavailable/zero. */
    return os_rss();
}

size_t cbm_mem_peak_rss(void) {
    size_t peak_rss = 0;