tree: https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-4.19 head: 0bd0742aae0ae9f23b26be2795b8458191236b5b commit: 9238e47da086f0075b28712a867544a7cda5e9e1 [56/57] FIXUP: FROMLIST: sched/fair: core wide vruntime comparison config: c6x-randconfig-r023-20200622 (attached as .config) compiler: c6x-elf-gcc (GCC) 9.3.0 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 git checkout 9238e47da086f0075b28712a867544a7cda5e9e1 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=c6x If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): kernel/sched/fair.c: In function 'cfs_prio_less': 535 | struct task_struct *p; | ^ At top level: kernel/sched/fair.c:7650:1: warning: 'pick_task_fair' defined but not used [-Wunused-function] 7650 | pick_task_fair(struct rq *rq) | ^~~~~~~~~~~~~~ vim +/p +535 kernel/sched/fair.c 1727d28632e4f12 Aaron Lu 2019-07-25 528 231822f7cf32291 Guenter Roeck 2020-06-16 529 #ifdef CONFIG_FAIR_GROUP_SCHED 1727d28632e4f12 Aaron Lu 2019-07-25 530 bool cfs_prio_less(struct task_struct *a, struct task_struct *b) 1727d28632e4f12 Aaron Lu 2019-07-25 531 { 1727d28632e4f12 Aaron Lu 2019-07-25 532 struct sched_entity *sea = &a->se; 1727d28632e4f12 Aaron Lu 2019-07-25 533 struct sched_entity *seb = &b->se; 1727d28632e4f12 Aaron Lu 2019-07-25 534 bool samecpu = task_cpu(a) == task_cpu(b); 1727d28632e4f12 Aaron Lu 2019-07-25 @535 struct task_struct *p; 1727d28632e4f12 Aaron Lu 2019-07-25 536 s64 delta; 1727d28632e4f12 Aaron Lu 2019-07-25 537 1727d28632e4f12 Aaron Lu 2019-07-25 538 if (samecpu) { 1727d28632e4f12 Aaron Lu 2019-07-25 539 /* vruntime is per cfs_rq */ 1727d28632e4f12 Aaron Lu 2019-07-25 540 while (!is_same_group(sea, seb)) { 1727d28632e4f12 Aaron Lu 2019-07-25 541 int sea_depth = sea->depth; 1727d28632e4f12 Aaron Lu 2019-07-25 542 int seb_depth = seb->depth; 1727d28632e4f12 Aaron Lu 2019-07-25 543 1727d28632e4f12 Aaron Lu 2019-07-25 544 if (sea_depth >= seb_depth) 1727d28632e4f12 Aaron Lu 2019-07-25 545 sea = parent_entity(sea); 1727d28632e4f12 Aaron Lu 2019-07-25 546 if (sea_depth <= seb_depth) 1727d28632e4f12 Aaron Lu 2019-07-25 547 seb = parent_entity(seb); 1727d28632e4f12 Aaron Lu 2019-07-25 548 } 1727d28632e4f12 Aaron Lu 2019-07-25 549 1727d28632e4f12 Aaron Lu 2019-07-25 550 delta = (s64)(sea->vruntime - seb->vruntime); 1727d28632e4f12 Aaron Lu 2019-07-25 551 goto out; 1727d28632e4f12 Aaron Lu 2019-07-25 552 } 1727d28632e4f12 Aaron Lu 2019-07-25 553 1727d28632e4f12 Aaron Lu 2019-07-25 554 /* crosscpu: compare root level se's vruntime to decide priority */ 1727d28632e4f12 Aaron Lu 2019-07-25 555 while (sea->parent) 1727d28632e4f12 Aaron Lu 2019-07-25 556 sea = sea->parent; 1727d28632e4f12 Aaron Lu 2019-07-25 557 while (seb->parent) 1727d28632e4f12 Aaron Lu 2019-07-25 558 seb = seb->parent; 1727d28632e4f12 Aaron Lu 2019-07-25 559 delta = (s64)(sea->vruntime - seb->vruntime); 1727d28632e4f12 Aaron Lu 2019-07-25 560 1727d28632e4f12 Aaron Lu 2019-07-25 561 out: 1727d28632e4f12 Aaron Lu 2019-07-25 562 p = delta > 0 ? b : a; 1727d28632e4f12 Aaron Lu 2019-07-25 563 1727d28632e4f12 Aaron Lu 2019-07-25 564 return delta > 0; 1727d28632e4f12 Aaron Lu 2019-07-25 565 } 231822f7cf32291 Guenter Roeck 2020-06-16 566 #endif /* CONFIG_FAIR_GROUP_SCHED */ 1727d28632e4f12 Aaron Lu 2019-07-25 567 :::::: The code at line 535 was first introduced by commit :::::: 1727d28632e4f124f314bc19ad4f40ec183fe60e FROMLIST: sched/fair: core wide vruntime comparison :::::: TO: Aaron Lu <aaron.lu(a)linux.alibaba.com&gt; :::::: CC: Commit Bot <commit-bot(a)chromium.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org