Hi Ming, kernel test robot noticed the following build warnings: [auto build test WARNING on axboe-block/for-next] [also build test WARNING on linus/master v6.12-rc3 next-20241018] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Ming-Lei/block-model-freeze-enter-queue-as-rwsem-for-supporting-lockdep/20241018-093704 base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next patch link: https://lore.kernel.org/r/20241018013542.3013963-1-ming.lei%40redhat.com patch subject: [PATCH] block: model freeze & enter queue as rwsem for supporting lockdep config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20241019/202410190214.KgZovHXy-lkp@xxxxxxxxx/config) compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241019/202410190214.KgZovHXy-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/202410190214.KgZovHXy-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> block/blk-mq.c:125:6: warning: variable 'sub_class' set but not used [-Wunused-but-set-variable] 125 | int sub_class; | ^ 1 warning generated. vim +/sub_class +125 block/blk-mq.c 122 123 void blk_freeze_queue_start(struct request_queue *q) 124 { > 125 int sub_class; 126 127 mutex_lock(&q->mq_freeze_lock); 128 sub_class = q->mq_freeze_depth; 129 if (++q->mq_freeze_depth == 1) { 130 percpu_ref_kill(&q->q_usage_counter); 131 mutex_unlock(&q->mq_freeze_lock); 132 if (queue_is_mq(q)) 133 blk_mq_run_hw_queues(q, false); 134 } else { 135 mutex_unlock(&q->mq_freeze_lock); 136 } 137 /* 138 * model as down_write_trylock() so that two concurrent freeze queue 139 * can be allowed 140 */ 141 if (blk_queue_freeze_lockdep(q)) 142 rwsem_acquire(&q->q_usage_counter_map, sub_class, 1, _RET_IP_); 143 } 144 EXPORT_SYMBOL_GPL(blk_freeze_queue_start); 145 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
