tree: https://github.com/0day-ci/linux/commits/UPDATE-20210315-111255/Yunsheng-... head: 17026ba24c376b0b696df0a97b38f7b0462bc486 commit: 17026ba24c376b0b696df0a97b38f7b0462bc486 net: sched: implement TCQ_F_CAN_BYPASS for lockless qdisc date: 2 hours ago config: x86_64-randconfig-s022-20210315 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-262-g5e674421-dirty # https://github.com/0day-ci/linux/commit/17026ba24c376b0b696df0a97b38f7b04... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review UPDATE-20210315-111255/Yunsheng-Lin/net-sched-implement-TCQ_F_CAN_BYPASS-for-lockless-qdisc/20210313-104858 git checkout 17026ba24c376b0b696df0a97b38f7b0462bc486 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; "sparse warnings: (new ones prefixed by >>)" net/sched/sch_generic.c:195:9: sparse: sparse: context imbalance in 'try_bulk_dequeue_skb_slow' - different lock contexts for basic block net/sched/sch_generic.c:272:28: sparse: sparse: context imbalance in 'dequeue_skb' - different lock contexts for basic block net/sched/sch_generic.c:311:28: sparse: sparse: context imbalance in 'sch_direct_xmit' - unexpected unlock net/sched/sch_generic.c:1170:13: sparse: sparse: context imbalance in 'dev_reset_queue' - different lock contexts for basic block vim +/sch_may_need_requeuing +149 net/sched/sch_generic.c 70e57d5e3f8ec7 John Fastabend 2017-12-07 119 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 120 static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) c716a81ab946c6 Jamal Hadi Salim 2007-06-10 121 { 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 122 spinlock_t *lock = NULL; 6252352d16f7b4 Jarek Poplawski 2008-10-06 123 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 124 if (q->flags & TCQ_F_NOLOCK) { 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 125 lock = qdisc_lock(q); 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 126 spin_lock(lock); c716a81ab946c6 Jamal Hadi Salim 2007-06-10 127 } c716a81ab946c6 Jamal Hadi Salim 2007-06-10 128 9540d977618c31 Wei Yongjun 2017-12-27 129 while (skb) { 9540d977618c31 Wei Yongjun 2017-12-27 130 struct sk_buff *next = skb->next; 9540d977618c31 Wei Yongjun 2017-12-27 131 a53851e2c3218a John Fastabend 2017-12-07 132 __skb_queue_tail(&q->gso_skb, skb); a53851e2c3218a John Fastabend 2017-12-07 133 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 134 /* it's still part of the queue */ 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 135 if (qdisc_is_percpu_stats(q)) { a53851e2c3218a John Fastabend 2017-12-07 136 qdisc_qstats_cpu_requeues_inc(q); a53851e2c3218a John Fastabend 2017-12-07 137 qdisc_qstats_cpu_backlog_inc(q, skb); 73eb628ddfd388 Paolo Abeni 2019-04-10 138 qdisc_qstats_cpu_qlen_inc(q); 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 139 } else { 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 140 q->qstats.requeues++; 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 141 qdisc_qstats_backlog_inc(q, skb); 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 142 q->q.qlen++; 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 143 } 9540d977618c31 Wei Yongjun 2017-12-27 144 9540d977618c31 Wei Yongjun 2017-12-27 145 skb = next; 9540d977618c31 Wei Yongjun 2017-12-27 146 } 9c01c9f1f2a3dd Paolo Abeni 2019-04-10 147 if (lock) 9540d977618c31 Wei Yongjun 2017-12-27 148 spin_unlock(lock); a53851e2c3218a John Fastabend 2017-12-07 @149 __netif_schedule(q); a53851e2c3218a John Fastabend 2017-12-07 150 } a53851e2c3218a John Fastabend 2017-12-07 151 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org