tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 3c3550371ac3e9d3326c8263a6eb52d3bb0b43a8 commit: bccfa644c1b98b9d6fa102a39a10a1c52811fd0c [15647/22256] sched/fair: Steal work from an overloaded CPU when CPU goes idle config: x86_64-randconfig-003-20240430 (https://download.01.org/0day-ci/archive/20240430/202404300955.dFOHBkZ8-lkp@i...) compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240430/202404300955.dFOHBkZ8-lkp@i...) 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@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202404300955.dFOHBkZ8-lkp@intel.com/ All warnings (new ones prefixed by >>): kernel/sched/fair.c:2548:6: warning: no previous prototype for 'task_numa_work' [-Wmissing-prototypes] 2548 | void task_numa_work(struct callback_head *work) | ^~~~~~~~~~~~~~ kernel/sched/fair.c:2694:6: warning: no previous prototype for 'task_tick_numa' [-Wmissing-prototypes] 2694 | void task_tick_numa(struct rq *rq, struct task_struct *curr) | ^~~~~~~~~~~~~~ kernel/sched/fair.c:3658:6: warning: no previous prototype for 'sync_entity_load_avg' [-Wmissing-prototypes] 3658 | void sync_entity_load_avg(struct sched_entity *se) | ^~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:3671:6: warning: no previous prototype for 'remove_entity_load_avg' [-Wmissing-prototypes] 3671 | void remove_entity_load_avg(struct sched_entity *se) | ^~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'update_blocked_averages': kernel/sched/fair.c:7626:14: warning: variable 'done' set but not used [-Wunused-but-set-variable] 7626 | bool done = true; | ^~~~ In function 'group_faults_priv', inlined from 'task_scan_max' at kernel/sched/fair.c:1175:27: kernel/sched/fair.c:1307:37: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1307 | faults += ng->faults[task_faults_idx(NUMA_MEM, node, 1)]; | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'task_scan_max': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults_shared', inlined from 'task_scan_max' at kernel/sched/fair.c:1174:26: kernel/sched/fair.c:1319:37: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1319 | faults += ng->faults[task_faults_idx(NUMA_MEM, node, 0)]; | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'task_scan_max': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults_priv', inlined from 'task_scan_start' at kernel/sched/fair.c:1151:27: kernel/sched/fair.c:1307:37: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1307 | faults += ng->faults[task_faults_idx(NUMA_MEM, node, 1)]; | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'task_scan_start': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults_shared', inlined from 'task_scan_start' at kernel/sched/fair.c:1150:26: kernel/sched/fair.c:1319:37: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1319 | faults += ng->faults[task_faults_idx(NUMA_MEM, node, 0)]; | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'task_scan_start': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In file included from include/linux/bitops.h:19, from include/linux/kernel.h:11, from arch/x86/include/asm/percpu.h:45, from arch/x86/include/asm/current.h:6, from include/linux/sched.h:12, from kernel/sched/sched.h:5, from kernel/sched/fair.c:23: In function 'sparsemask_test_elem', inlined from 'try_steal' at kernel/sched/fair.c:10007:8: kernel/sched/sparsemask.h:53:10: warning: array subscript <unknown> is outside array bounds of 'const struct sparsemask_chunk[0]' [-Warray-bounds=] 53 | (&(mask)->chunks[SMASK_INDEX((mask), (elem))].word) arch/x86/include/asm/bitops.h:341:37: note: in definition of macro 'test_bit' 341 | : variable_test_bit((nr), (addr))) | ^~~~ kernel/sched/sparsemask.h:191:48: note: in expansion of macro 'SMASK_WORD' 191 | return test_bit(SMASK_BIT(mask, elem), SMASK_WORD(mask, elem)); | ^~~~~~~~~~ In file included from kernel/sched/fair.c:24: kernel/sched/sparsemask.h: In function 'try_steal': kernel/sched/sparsemask.h:45:33: note: while referencing 'chunks' 45 | struct sparsemask_chunk chunks[0]; /* embedded array of chunks */ | ^~~~~~ In function 'sparsemask_next', inlined from 'try_steal' at kernel/sched/fair.c:10018:2: kernel/sched/sparsemask.h:98:17: warning: array subscript <unknown> is outside array bounds of 'const struct sparsemask_chunk[0]' [-Warray-bounds=] 98 | chunk = &mask->chunks[_SMASK_INDEX(density, next)]; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/sparsemask.h: In function 'try_steal': kernel/sched/sparsemask.h:45:33: note: while referencing 'chunks' 45 | struct sparsemask_chunk chunks[0]; /* embedded array of chunks */ | ^~~~~~ In function 'sparsemask_next', inlined from 'try_steal' at kernel/sched/fair.c:10018:2:

...

kernel/sched/sparsemask.h:98:17: warning: array subscript 0 is outside array bounds of 'const struct sparsemask_chunk[0]' [-Warray-bounds=] 98 | chunk = &mask->chunks[_SMASK_INDEX(density, next)]; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/sparsemask.h: In function 'try_steal': kernel/sched/sparsemask.h:45:33: note: while referencing 'chunks' 45 | struct sparsemask_chunk chunks[0]; /* embedded array of chunks */ | ^~~~~~ In function 'sparsemask_next', inlined from 'try_steal' at kernel/sched/fair.c:10018:2: kernel/sched/sparsemask.h:98:30: warning: array subscript <unknown> is outside array bounds of 'const struct sparsemask_chunk[0]' [-Warray-bounds=] 98 | chunk = &mask->chunks[_SMASK_INDEX(density, next)]; | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/sparsemask.h: In function 'try_steal': kernel/sched/sparsemask.h:45:33: note: while referencing 'chunks' 45 | struct sparsemask_chunk chunks[0]; /* embedded array of chunks */ | ^~~~~~ kernel/sched/fair.c: In function 'task_numa_group': kernel/sched/fair.c:2335:36: warning: array subscript i is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 2335 | grp->faults[i] = p->numa_faults[i]; | ~~~~~~~~~~~^~~ kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ kernel/sched/fair.c:2393:31: warning: array subscript i is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 2393 | my_grp->faults[i] -= p->numa_faults[i]; | ~~~~~~~~~~~~~~^~~ kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ kernel/sched/fair.c:2393:31: warning: array subscript i is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 2393 | my_grp->faults[i] -= p->numa_faults[i]; | ~~~~~~~~~~~~~~^~~ kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ kernel/sched/fair.c:2394:28: warning: array subscript i is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 2394 | grp->faults[i] += p->numa_faults[i]; | ~~~~~~~~~~~^~~ kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ kernel/sched/fair.c:2394:28: warning: array subscript i is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 2394 | grp->faults[i] += p->numa_faults[i]; | ~~~~~~~~~~~^~~ kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'sparsemask_clear_elem', inlined from 'overload_clear.part.0' at kernel/sched/fair.c:3834:3: kernel/sched/sparsemask.h:53:10: warning: array subscript <unknown> is outside array bounds of 'struct sparsemask_chunk[0]' [-Warray-bounds=] 53 | (&(mask)->chunks[SMASK_INDEX((mask), (elem))].word) | ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/sparsemask.h:186:41: note: in expansion of macro 'SMASK_WORD' 186 | clear_bit(SMASK_BIT(dst, elem), SMASK_WORD(dst, elem)); | ^~~~~~~~~~ kernel/sched/sparsemask.h: In function 'overload_clear.part.0': kernel/sched/sparsemask.h:45:33: note: while referencing 'chunks' 45 | struct sparsemask_chunk chunks[0]; /* embedded array of chunks */ | ^~~~~~ In function 'group_faults', inlined from 'score_nearby_nodes.part.0' at kernel/sched/fair.c:1381:13: kernel/sched/fair.c:1291:26: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1291 | return ng->faults[task_faults_idx(NUMA_MEM, nid, 0)] + | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'score_nearby_nodes.part.0': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults', inlined from 'score_nearby_nodes.part.0' at kernel/sched/fair.c:1381:13: kernel/sched/fair.c:1292:27: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1292 | ng->faults[task_faults_idx(NUMA_MEM, nid, 1)]; | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'score_nearby_nodes.part.0': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults', inlined from 'preferred_group_nid' at kernel/sched/fair.c:2161:16: kernel/sched/fair.c:1291:26: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1291 | return ng->faults[task_faults_idx(NUMA_MEM, nid, 0)] + | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'preferred_group_nid': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults', inlined from 'preferred_group_nid' at kernel/sched/fair.c:2161:16: kernel/sched/fair.c:1292:27: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1292 | ng->faults[task_faults_idx(NUMA_MEM, nid, 1)]; | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c: In function 'preferred_group_nid': kernel/sched/fair.c:1083:23: note: while referencing 'faults' 1083 | unsigned long faults[0]; | ^~~~~~ In function 'group_faults', inlined from 'group_weight' at kernel/sched/fair.c:1441:11, inlined from 'preferred_group_nid' at kernel/sched/fair.c:2125:12: kernel/sched/fair.c:1291:26: warning: array subscript <unknown> is outside array bounds of 'long unsigned int[0]' [-Warray-bounds=] 1291 | return ng->faults[task_faults_idx(NUMA_MEM, nid, 0)] + | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +98 kernel/sched/sparsemask.h 6866be5a3aff4b Steve Sistare 2021-04-14 47 6866be5a3aff4b Steve Sistare 2021-04-14 48 #define _SMASK_INDEX(density, elem) ((elem) >> (density)) 6866be5a3aff4b Steve Sistare 2021-04-14 49 #define _SMASK_BIT(density, elem) ((elem) & ((1U << (density)) - 1U)) 6866be5a3aff4b Steve Sistare 2021-04-14 50 #define SMASK_INDEX(mask, elem) _SMASK_INDEX((mask)->density, elem) 6866be5a3aff4b Steve Sistare 2021-04-14 51 #define SMASK_BIT(mask, elem) _SMASK_BIT((mask)->density, elem) 6866be5a3aff4b Steve Sistare 2021-04-14 52 #define SMASK_WORD(mask, elem) \ 6866be5a3aff4b Steve Sistare 2021-04-14 53 (&(mask)->chunks[SMASK_INDEX((mask), (elem))].word) 6866be5a3aff4b Steve Sistare 2021-04-14 54 6866be5a3aff4b Steve Sistare 2021-04-14 55 /* 6866be5a3aff4b Steve Sistare 2021-04-14 56 * sparsemask_next() - Return the next one bit in a bitmap, starting at a 6866be5a3aff4b Steve Sistare 2021-04-14 57 * specified position and wrapping from the last bit to the first, up to but 6866be5a3aff4b Steve Sistare 2021-04-14 58 * not including a specified origin. This is a helper, so do not call it 6866be5a3aff4b Steve Sistare 2021-04-14 59 * directly. 6866be5a3aff4b Steve Sistare 2021-04-14 60 * 6866be5a3aff4b Steve Sistare 2021-04-14 61 * @mask: Bitmap to search. 6866be5a3aff4b Steve Sistare 2021-04-14 62 * @origin: Origin. 6866be5a3aff4b Steve Sistare 2021-04-14 63 * @prev: Previous bit. Start search after this bit number. 6866be5a3aff4b Steve Sistare 2021-04-14 64 * If -1, start search at @origin. 6866be5a3aff4b Steve Sistare 2021-04-14 65 * 6866be5a3aff4b Steve Sistare 2021-04-14 66 * Return: the bit number, else mask->nelems if no bits are set in the range. 6866be5a3aff4b Steve Sistare 2021-04-14 67 */ 6866be5a3aff4b Steve Sistare 2021-04-14 68 static inline int 6866be5a3aff4b Steve Sistare 2021-04-14 69 sparsemask_next(const struct sparsemask *mask, int origin, int prev) 6866be5a3aff4b Steve Sistare 2021-04-14 70 { 6866be5a3aff4b Steve Sistare 2021-04-14 71 int density = mask->density; 6866be5a3aff4b Steve Sistare 2021-04-14 72 int bits_per_word = 1U << density; 6866be5a3aff4b Steve Sistare 2021-04-14 73 const struct sparsemask_chunk *chunk; 6866be5a3aff4b Steve Sistare 2021-04-14 74 int nelems = mask->nelems; 6866be5a3aff4b Steve Sistare 2021-04-14 75 int next, bit, nbits; 6866be5a3aff4b Steve Sistare 2021-04-14 76 unsigned long word; 6866be5a3aff4b Steve Sistare 2021-04-14 77 6866be5a3aff4b Steve Sistare 2021-04-14 78 /* Calculate number of bits to be searched. */ 6866be5a3aff4b Steve Sistare 2021-04-14 79 if (prev == -1) { 6866be5a3aff4b Steve Sistare 2021-04-14 80 nbits = nelems; 6866be5a3aff4b Steve Sistare 2021-04-14 81 next = origin; 6866be5a3aff4b Steve Sistare 2021-04-14 82 } else if (prev < origin) { 6866be5a3aff4b Steve Sistare 2021-04-14 83 nbits = origin - prev; 6866be5a3aff4b Steve Sistare 2021-04-14 84 next = prev + 1; 6866be5a3aff4b Steve Sistare 2021-04-14 85 } else { 6866be5a3aff4b Steve Sistare 2021-04-14 86 nbits = nelems - prev + origin - 1; 6866be5a3aff4b Steve Sistare 2021-04-14 87 next = prev + 1; 6866be5a3aff4b Steve Sistare 2021-04-14 88 } 6866be5a3aff4b Steve Sistare 2021-04-14 89 6866be5a3aff4b Steve Sistare 2021-04-14 90 if (unlikely(next >= nelems)) 6866be5a3aff4b Steve Sistare 2021-04-14 91 return nelems; 6866be5a3aff4b Steve Sistare 2021-04-14 92 6866be5a3aff4b Steve Sistare 2021-04-14 93 /* 6866be5a3aff4b Steve Sistare 2021-04-14 94 * Fetch and adjust first word. Clear word bits below @next, and round 6866be5a3aff4b Steve Sistare 2021-04-14 95 * @next down to @bits_per_word boundary because later ffs will add 6866be5a3aff4b Steve Sistare 2021-04-14 96 * those bits back. 6866be5a3aff4b Steve Sistare 2021-04-14 97 */ 6866be5a3aff4b Steve Sistare 2021-04-14 @98 chunk = &mask->chunks[_SMASK_INDEX(density, next)]; 6866be5a3aff4b Steve Sistare 2021-04-14 99 bit = _SMASK_BIT(density, next); 6866be5a3aff4b Steve Sistare 2021-04-14 100 word = chunk->word & (~0UL << bit); 6866be5a3aff4b Steve Sistare 2021-04-14 101 next -= bit; 6866be5a3aff4b Steve Sistare 2021-04-14 102 nbits += bit; 6866be5a3aff4b Steve Sistare 2021-04-14 103 6866be5a3aff4b Steve Sistare 2021-04-14 104 while (!word) { 6866be5a3aff4b Steve Sistare 2021-04-14 105 next += bits_per_word; 6866be5a3aff4b Steve Sistare 2021-04-14 106 nbits -= bits_per_word; 6866be5a3aff4b Steve Sistare 2021-04-14 107 if (nbits <= 0) 6866be5a3aff4b Steve Sistare 2021-04-14 108 return nelems; 6866be5a3aff4b Steve Sistare 2021-04-14 109 6866be5a3aff4b Steve Sistare 2021-04-14 110 if (next >= nelems) { 6866be5a3aff4b Steve Sistare 2021-04-14 111 chunk = mask->chunks; 6866be5a3aff4b Steve Sistare 2021-04-14 112 nbits -= (next - nelems); 6866be5a3aff4b Steve Sistare 2021-04-14 113 next = 0; 6866be5a3aff4b Steve Sistare 2021-04-14 114 } else { 6866be5a3aff4b Steve Sistare 2021-04-14 115 chunk++; 6866be5a3aff4b Steve Sistare 2021-04-14 116 } 6866be5a3aff4b Steve Sistare 2021-04-14 117 word = chunk->word; 6866be5a3aff4b Steve Sistare 2021-04-14 118 } 6866be5a3aff4b Steve Sistare 2021-04-14 119 6866be5a3aff4b Steve Sistare 2021-04-14 120 next += __ffs(word); 6866be5a3aff4b Steve Sistare 2021-04-14 121 if (next >= origin && prev != -1) 6866be5a3aff4b Steve Sistare 2021-04-14 122 return nelems; 6866be5a3aff4b Steve Sistare 2021-04-14 123 return next; 6866be5a3aff4b Steve Sistare 2021-04-14 124 } 6866be5a3aff4b Steve Sistare 2021-04-14 125 :::::: The code at line 98 was first introduced by commit :::::: 6866be5a3aff4bbd949059927d8f8790be53e3dd sched: Provide sparsemask, a reduced contention bitmap :::::: TO: Steve Sistare <steven.sistare@oracle.com> :::::: CC: Cheng Jian <cj.chengjian@huawei.com> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki