Function cbm_mem_peak_rss

src/foundation/mem.c:472–491

}

size_t cbm_mem_peak_rss(void) {
    size_t peak_rss = 0;
    mi_process_info(NULL, NULL, NULL, NULL, &peak_rss, NULL, NULL, NULL);
    /* Peak RSS is by definition >= current RSS. On Linux cbm_mem_rss() reads the
     * live /proc/self/statm value (page-granular), while mimalloc's peak_rss
     * comes from getrusage's ru_maxrss (KB-granular, and it can lag the live
     * statm read by a few pages). Reading the two sources independently lets a
     * fresh current read momentarily exceed the reported peak, breaking the
     * peak >= current invariant. Reconcile them: the true peak is at least the
     * current RSS. (Not observable on macOS, where both come from mimalloc.) */
    size_t current = cbm_mem_rss();
    if (current > peak_rss) {
        peak_rss = current;
    }
    if (peak_rss > 0) {
        return peak_rss;
    }
    /* No OS fallback for peak — return current as best approximation */
    return os_rss();
}

size_t cbm_mem_budget(void) {
    return g_budget;