Messages in this thread | | | Date | Wed, 11 May 2022 00:37:23 +0800 | From | kernel test robot <> | Subject | [yu-chen-surf:sis 1/1] kernel/sched/fair.c:9317:12: warning: comparison of distinct pointer types ('typeof (0) *' (aka 'int *') and 'typeof ((nr_llc * y) / (1L << 10)) *' (aka 'long *')) |
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tree: https://github.com/yu-chen-surf/linux.git sis head: e99eab1b5fbda9474ad4fe9074983f2d2169923b commit: e99eab1b5fbda9474ad4fe9074983f2d2169923b [1/1] sched/fair: Introduce SIS_UTIL to search idle CPU based on sum of util_avg config: arm-milbeaut_m10v_defconfig (https://download.01.org/0day-ci/archive/20220511/202205110033.NNmqSG7c-lkp@intel.com/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 18dd123c56754edf62c7042dcf23185c3727610f) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://github.com/yu-chen-surf/linux/commit/e99eab1b5fbda9474ad4fe9074983f2d2169923b git remote add yu-chen-surf https://github.com/yu-chen-surf/linux.git git fetch --no-tags yu-chen-surf sis git checkout e99eab1b5fbda9474ad4fe9074983f2d2169923b # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash kernel/sched/
If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
kernel/sched/fair.c:5530:6: warning: no previous prototype for function 'init_cfs_bandwidth' [-Wmissing-prototypes] void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} ^ kernel/sched/fair.c:5530:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} ^ static >> kernel/sched/fair.c:9317:12: warning: comparison of distinct pointer types ('typeof (0) *' (aka 'int *') and 'typeof ((nr_llc * y) / (1L << 10)) *' (aka 'long *')) [-Wcompare-distinct-pointer-types] nr_scan = max(0, (nr_llc * y) / SCHED_CAPACITY_SCALE); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/minmax.h:52:19: note: expanded from macro 'max' #define max(x, y) __careful_cmp(x, y, >) ^~~~~~~~~~~~~~~~~~~~~~ include/linux/minmax.h:36:24: note: expanded from macro '__careful_cmp' __builtin_choose_expr(__safe_cmp(x, y), \ ^~~~~~~~~~~~~~~~ include/linux/minmax.h:26:4: note: expanded from macro '__safe_cmp' (__typecheck(x, y) && __no_side_effects(x, y)) ^~~~~~~~~~~~~~~~~ include/linux/minmax.h:20:28: note: expanded from macro '__typecheck' (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~ kernel/sched/fair.c:10704:6: warning: no previous prototype for function 'nohz_balance_enter_idle' [-Wmissing-prototypes] void nohz_balance_enter_idle(int cpu) ^ kernel/sched/fair.c:10704:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void nohz_balance_enter_idle(int cpu) ^ static kernel/sched/fair.c:11826:6: warning: no previous prototype for function 'free_fair_sched_group' [-Wmissing-prototypes] void free_fair_sched_group(struct task_group *tg) { } ^ kernel/sched/fair.c:11826:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void free_fair_sched_group(struct task_group *tg) { } ^ static kernel/sched/fair.c:11828:5: warning: no previous prototype for function 'alloc_fair_sched_group' [-Wmissing-prototypes] int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) ^ kernel/sched/fair.c:11828:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) ^ static kernel/sched/fair.c:11833:6: warning: no previous prototype for function 'online_fair_sched_group' [-Wmissing-prototypes] void online_fair_sched_group(struct task_group *tg) { } ^ kernel/sched/fair.c:11833:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void online_fair_sched_group(struct task_group *tg) { } ^ static kernel/sched/fair.c:11835:6: warning: no previous prototype for function 'unregister_fair_sched_group' [-Wmissing-prototypes] void unregister_fair_sched_group(struct task_group *tg) { } ^ kernel/sched/fair.c:11835:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void unregister_fair_sched_group(struct task_group *tg) { } ^ static kernel/sched/fair.c:507:20: warning: unused function 'list_del_leaf_cfs_rq' [-Wunused-function] static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) ^ kernel/sched/fair.c:528:19: warning: unused function 'tg_is_idle' [-Wunused-function] static inline int tg_is_idle(struct task_group *tg) ^ kernel/sched/fair.c:5511:20: warning: unused function 'sync_throttle' [-Wunused-function] static inline void sync_throttle(struct task_group *tg, int cpu) {} ^ kernel/sched/fair.c:5536:37: warning: unused function 'tg_cfs_bandwidth' [-Wunused-function] static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) ^ kernel/sched/fair.c:5540:20: warning: unused function 'destroy_cfs_bandwidth' [-Wunused-function] static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} ^ 12 warnings generated.
vim +9317 kernel/sched/fair.c
9267 9268 static inline void update_idle_cpu_scan(struct lb_env *env, 9269 unsigned long sum_util) 9270 { 9271 struct sched_domain_shared *sd_share; 9272 int nr_scan, nr_llc, x, y; 9273 9274 if (!sched_feat(SIS_UTIL)) 9275 return; 9276 /* 9277 * Update the number of CPUs to scan in LLC domain, which could 9278 * be used as a hint in select_idle_cpu(). The update of this hint 9279 * occurs during periodic load balancing, rather than frequent 9280 * newidle balance. 9281 */ 9282 nr_llc = per_cpu(sd_llc_size, env->dst_cpu); 9283 if (env->idle == CPU_NEWLY_IDLE || 9284 env->sd->span_weight != nr_llc) 9285 return; 9286 9287 sd_share = rcu_dereference(per_cpu(sd_llc_shared, env->dst_cpu)); 9288 if (!sd_share) 9289 return; 9290 9291 /* 9292 * The number of CPUs to search drops as sum_util increases, when 9293 * sum_util hits 85% or above, the scan stops. 9294 * The reason to choose 85% as the threshold is because this is the 9295 * imbalance_pct(117) when a LLC sched group is overloaded. 9296 * 9297 * let y = 1 - (x/0.85)^2 [1] 9298 * 9299 * y is the ratio of CPUs to be scanned in the LLC 9300 * domain, x is the ratio of sum_util compared to the 9301 * CPU capacity: 9302 * 9303 * x = sum_util / (nr_llc * SCHED_CAPACITY_SCALE) [2] 9304 * 9305 * Scale x by SCHED_CAPACITY_SCALE and [2] becomes: 9306 * 9307 * x = sum_util / nr_llc [3] 9308 * 9309 * and [1] becomes: 9310 * 9311 * y = (SCHED_CAPACITY_SCALE - (x*x)/740) / SCHED_CAPACITY_SCALE [4] 9312 * 9313 * then the number of CPUs to scan is nr_scan = nr_llc * y 9314 */ 9315 x = sum_util / nr_llc; 9316 y = SCHED_CAPACITY_SCALE - (x * x) / 740; > 9317 nr_scan = max(0, (nr_llc * y) / SCHED_CAPACITY_SCALE); 9318 WRITE_ONCE(sd_share->nr_idle_scan, nr_scan); 9319 } 9320
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