Hi Stefan, kernel test robot noticed the following build errors: [auto build test ERROR on 12d04a7bf0da67321229d2bc8b1a7074d65415a9] url: https://github.com/intel-lab-lkp/linux/commits/Stefan-Roesch/mm-ksm-add-ksm-advisor/20231205-075118 base: 12d04a7bf0da67321229d2bc8b1a7074d65415a9 patch link: https://lore.kernel.org/r/20231204234906.1237478-2-shr%40devkernel.io patch subject: [PATCH v3 1/4] mm/ksm: add ksm advisor config: i386-randconfig-011-20231206 (https://download.01.org/0day-ci/archive/20231206/202312062353.lBYSA7Eb-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231206/202312062353.lBYSA7Eb-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202312062353.lBYSA7Eb-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): ld: mm/ksm.o: in function `scan_time_advisor': >> mm/ksm.c:423: undefined reference to `__divdi3' >> ld: mm/ksm.c:435: undefined reference to `__divdi3' ld: mm/ksm.c:428: undefined reference to `__divdi3' vim +423 mm/ksm.c 383 384 /* 385 * The scan time advisor is based on the current scan rate and the target 386 * scan rate. 387 * 388 * new_pages_to_scan = pages_to_scan * (scan_time / target_scan_time) 389 * 390 * To avoid pertubations it calculates a change factor of previous changes. 391 * A new change factor is calculated for each iteration and it uses an 392 * exponentially weighted moving average. The new pages_to_scan value is 393 * multiplied with that change factor: 394 * 395 * new_pages_to_scan *= change facor 396 * 397 * In addition the new pages_to_scan value is capped by the max and min 398 * limits. 399 */ 400 static void scan_time_advisor(void) 401 { 402 unsigned int cpu_percent; 403 unsigned long cpu_time; 404 unsigned long cpu_time_diff; 405 unsigned long cpu_time_diff_ms; 406 unsigned long pages; 407 unsigned long per_page_cost; 408 unsigned long factor; 409 unsigned long change; 410 unsigned long last_scan_time; 411 s64 scan_time; 412 413 /* Convert scan time to seconds */ 414 scan_time = advisor_stop_scan(); 415 scan_time = div_s64(scan_time, MSEC_PER_SEC); 416 scan_time = scan_time ? scan_time : 1; 417 418 /* Calculate CPU consumption of ksmd background thread */ 419 cpu_time = task_sched_runtime(current); 420 cpu_time_diff = cpu_time - advisor_ctx.cpu_time; 421 cpu_time_diff_ms = cpu_time_diff / 1000 / 1000; 422 > 423 cpu_percent = (cpu_time_diff_ms * 100) / (scan_time * 1000); 424 cpu_percent = cpu_percent ? cpu_percent : 1; 425 last_scan_time = prev_scan_time(&advisor_ctx, scan_time); 426 427 /* Calculate scan time as percentage of target scan time */ 428 factor = ksm_advisor_target_scan_time * 100 / scan_time; 429 factor = factor ? factor : 1; 430 431 /* 432 * Calculate scan time as percentage of last scan time and use 433 * exponentially weighted average to smooth it 434 */ > 435 change = scan_time * 100 / last_scan_time; 436 change = change ? change : 1; 437 change = ewma(advisor_ctx.change, change); 438 439 /* Calculate new scan rate based on target scan rate. */ 440 pages = ksm_thread_pages_to_scan * 100 / factor; 441 /* Update pages_to_scan by weighted change percentage. */ 442 pages = pages * change / 100; 443 444 /* Cap new pages_to_scan value */ 445 per_page_cost = ksm_thread_pages_to_scan / cpu_percent; 446 per_page_cost = per_page_cost ? per_page_cost : 1; 447 448 pages = min(pages, per_page_cost * ksm_advisor_max_cpu); 449 pages = max(pages, per_page_cost * ksm_advisor_min_cpu); 450 pages = min(pages, ksm_advisor_max_pages); 451 452 /* Update advisor context */ 453 advisor_ctx.change = change; 454 advisor_ctx.scan_time = scan_time; 455 advisor_ctx.cpu_time = cpu_time; 456 457 ksm_thread_pages_to_scan = pages; 458 } 459 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
