Hi Xin, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on akpm-mm/mm-everything] url: https://github.com/intel-lab-lkp/linux/commits/Xin-Hao/mm-damon-simplify-scheme-create-in-damon_lru_sort_apply_parameters/20220911-005630 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything config: x86_64-allyesconfig compiler: gcc-11 (Debian 11.3.0-5) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/d9938ea4d14a88832eee655cda52401891778dd5 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Xin-Hao/mm-damon-simplify-scheme-create-in-damon_lru_sort_apply_parameters/20220911-005630 git checkout d9938ea4d14a88832eee655cda52401891778dd5 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash mm/damon/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot All warnings (new ones prefixed by >>): mm/damon/lru_sort.c: In function 'damon_lru_sort_apply_parameters': >> mm/damon/lru_sort.c:353:32: warning: unused variable 'next_scheme' [-Wunused-variable] 353 | struct damos *scheme, *next_scheme; | ^~~~~~~~~~~ vim +/next_scheme +353 mm/damon/lru_sort.c 40e983cca9274e SeongJae Park 2022-06-13 350 40e983cca9274e SeongJae Park 2022-06-13 351 static int damon_lru_sort_apply_parameters(void) 40e983cca9274e SeongJae Park 2022-06-13 352 { 40e983cca9274e SeongJae Park 2022-06-13 @353 struct damos *scheme, *next_scheme; 40e983cca9274e SeongJae Park 2022-06-13 354 struct damon_addr_range addr_range; 40e983cca9274e SeongJae Park 2022-06-13 355 unsigned int hot_thres, cold_thres; 40e983cca9274e SeongJae Park 2022-06-13 356 int err = 0; 40e983cca9274e SeongJae Park 2022-06-13 357 40e983cca9274e SeongJae Park 2022-06-13 358 err = damon_set_attrs(ctx, sample_interval, aggr_interval, 0, 40e983cca9274e SeongJae Park 2022-06-13 359 min_nr_regions, max_nr_regions); 40e983cca9274e SeongJae Park 2022-06-13 360 if (err) 40e983cca9274e SeongJae Park 2022-06-13 361 return err; 40e983cca9274e SeongJae Park 2022-06-13 362 40e983cca9274e SeongJae Park 2022-06-13 363 /* aggr_interval / sample_interval is the maximum nr_accesses */ 40e983cca9274e SeongJae Park 2022-06-13 364 hot_thres = aggr_interval / sample_interval * hot_thres_access_freq / 40e983cca9274e SeongJae Park 2022-06-13 365 1000; 40e983cca9274e SeongJae Park 2022-06-13 366 scheme = damon_lru_sort_new_hot_scheme(hot_thres); 40e983cca9274e SeongJae Park 2022-06-13 367 if (!scheme) 40e983cca9274e SeongJae Park 2022-06-13 368 return -ENOMEM; d9938ea4d14a88 Xin Hao 2022-09-11 369 err = damon_set_schemes(ctx, &scheme, 1); d9938ea4d14a88 Xin Hao 2022-09-11 370 if (err) d9938ea4d14a88 Xin Hao 2022-09-11 371 return err; 40e983cca9274e SeongJae Park 2022-06-13 372 40e983cca9274e SeongJae Park 2022-06-13 373 cold_thres = cold_min_age / aggr_interval; 40e983cca9274e SeongJae Park 2022-06-13 374 scheme = damon_lru_sort_new_cold_scheme(cold_thres); 40e983cca9274e SeongJae Park 2022-06-13 375 if (!scheme) 40e983cca9274e SeongJae Park 2022-06-13 376 return -ENOMEM; 40e983cca9274e SeongJae Park 2022-06-13 377 damon_add_scheme(ctx, scheme); 40e983cca9274e SeongJae Park 2022-06-13 378 40e983cca9274e SeongJae Park 2022-06-13 379 if (monitor_region_start > monitor_region_end) 40e983cca9274e SeongJae Park 2022-06-13 380 return -EINVAL; 40e983cca9274e SeongJae Park 2022-06-13 381 if (!monitor_region_start && !monitor_region_end && dd7ecfcf662cdf Xin Hao 2022-09-09 382 !damon_find_biggest_system_ram(&monitor_region_start, 40e983cca9274e SeongJae Park 2022-06-13 383 &monitor_region_end)) 40e983cca9274e SeongJae Park 2022-06-13 384 return -EINVAL; 40e983cca9274e SeongJae Park 2022-06-13 385 addr_range.start = monitor_region_start; 40e983cca9274e SeongJae Park 2022-06-13 386 addr_range.end = monitor_region_end; 40e983cca9274e SeongJae Park 2022-06-13 387 return damon_set_regions(target, &addr_range, 1); 40e983cca9274e SeongJae Park 2022-06-13 388 } 40e983cca9274e SeongJae Park 2022-06-13 389 -- 0-DAY CI Kernel Test Service https://01.org/lkp