CC: [email protected] TO: Frederic Weisbecker <[email protected]>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git rcu/dev-v2 head: 925ee3076eb694db893e2c6664d90ad8fb9cb6e5 commit: 5530b1d0d6817b6a7a51665390eb20cd25919ddf [5/13] rcu/nocb: Merge nocb_timer to the rdp leader :::::: branch date: 5 hours ago :::::: commit date: 5 hours ago config: x86_64-randconfig-s032-20210222 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-229-g60c1f270-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git/commit/?id=5530b1d0d6817b6a7a51665390eb20cd25919ddf git remote add dynticks https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git git fetch --no-tags dynticks rcu/dev-v2 git checkout 5530b1d0d6817b6a7a51665390eb20cd25919ddf # 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 <[email protected]> "sparse warnings: (new ones prefixed by >>)" kernel/rcu/tree.c: note: in included file: kernel/rcu/tree_plugin.h:1561:5: sparse: sparse: symbol 'nocb_nobypass_lim_per_jiffy' was not declared. Should it be static? kernel/rcu/tree.c:1455:9: sparse: sparse: context imbalance in 'rcu_start_this_gp' - different lock contexts for basic block kernel/rcu/tree.c:1867:9: sparse: sparse: context imbalance in 'rcu_gp_init' - different lock contexts for basic block kernel/rcu/tree.c:2646:9: sparse: sparse: context imbalance in 'force_qs_rnp' - different lock contexts for basic block kernel/rcu/tree.c:2699:25: sparse: sparse: context imbalance in 'rcu_force_quiescent_state' - unexpected unlock kernel/rcu/tree.c:2729:30: sparse: sparse: context imbalance in 'rcu_core' - different lock contexts for basic block kernel/rcu/tree.c: note: in included file: kernel/rcu/tree_stall.h:318:9: sparse: sparse: context imbalance in 'rcu_print_task_stall' - unexpected unlock kernel/rcu/tree_stall.h:540:9: sparse: sparse: context imbalance in 'print_other_cpu_stall' - different lock contexts for basic block kernel/rcu/tree_stall.h:821:17: sparse: sparse: context imbalance in 'rcu_check_gp_start_stall' - different lock contexts for basic block kernel/rcu/tree.c: note: in included file: kernel/rcu/tree_exp.h:189:9: sparse: sparse: context imbalance in '__rcu_report_exp_rnp' - different lock contexts for basic block kernel/rcu/tree.c: note: in included file: kernel/rcu/tree_plugin.h:1607:16: sparse: sparse: context imbalance in 'rcu_nocb_bypass_trylock' - wrong count at exit kernel/rcu/tree_plugin.h:1624:13: sparse: sparse: context imbalance in 'rcu_nocb_lock' - wrong count at exit kernel/rcu/tree_plugin.h:1639:17: sparse: sparse: context imbalance in 'rcu_nocb_unlock' - unexpected unlock kernel/rcu/tree_plugin.h:1652:17: sparse: sparse: context imbalance in 'rcu_nocb_unlock_irqrestore' - unexpected unlock kernel/rcu/tree_plugin.h:1784:9: sparse: sparse: context imbalance in 'rcu_nocb_do_flush_bypass' - unexpected unlock kernel/rcu/tree_plugin.h:1799:13: sparse: sparse: context imbalance in 'rcu_nocb_flush_bypass' - wrong count at exit kernel/rcu/tree_plugin.h:1961:13: sparse: sparse: context imbalance in '__call_rcu_nocb_wake' - wrong count at exit kernel/rcu/tree_plugin.h:2030:9: sparse: sparse: context imbalance in 'do_nocb_bypass_wakeup_timer' - different lock contexts for basic block kernel/rcu/tree_plugin.h:2107:9: sparse: sparse: context imbalance in 'nocb_gp_wait' - different lock contexts for basic block kernel/rcu/tree_plugin.h:2329:9: sparse: sparse: context imbalance in 'nocb_cb_wait' - wrong count at exit kernel/rcu/tree_plugin.h:2445:9: sparse: sparse: context imbalance in 'rdp_offload_toggle' - wrong count at exit >> kernel/rcu/tree_plugin.h:2483:32: sparse: sparse: context imbalance in >> 'rcu_nocb_rdp_deoffload' - different lock contexts for basic block vim +/rcu_nocb_rdp_deoffload +2483 kernel/rcu/tree_plugin.h 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2447 d5583036705d111 Frederic Weisbecker 2021-01-28 2448 static long rcu_nocb_rdp_deoffload(void *arg) 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2449 { d5583036705d111 Frederic Weisbecker 2021-01-28 2450 struct rcu_data *rdp = arg; 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2451 struct rcu_segcblist *cblist = &rdp->cblist; 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2452 unsigned long flags; 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2453 int ret; 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2454 d5583036705d111 Frederic Weisbecker 2021-01-28 2455 WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); d5583036705d111 Frederic Weisbecker 2021-01-28 2456 f759081e8f5ac64 Paul E. McKenney 2020-12-21 2457 pr_info("De-offloading %d\n", rdp->cpu); 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2458 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2459 rcu_nocb_lock_irqsave(rdp, flags); 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2460 /* 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2461 * Flush once and for all now. This suffices because we are 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2462 * running on the target CPU holding ->nocb_lock (thus having 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2463 * interrupts disabled), and because rdp_offload_toggle() 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2464 * invokes rcu_segcblist_offload(), which clears SEGCBLIST_OFFLOADED. 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2465 * Thus future calls to rcu_segcblist_completely_offloaded() will 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2466 * return false, which means that future calls to rcu_nocb_try_bypass() 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2467 * will refuse to put anything into the bypass. 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2468 */ 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2469 WARN_ON_ONCE(!rcu_nocb_flush_bypass(rdp, NULL, jiffies)); 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2470 ret = rdp_offload_toggle(rdp, false, flags); 5bb39dc956f3d4f Frederic Weisbecker 2020-11-13 2471 swait_event_exclusive(rdp->nocb_state_wq, 5bb39dc956f3d4f Frederic Weisbecker 2020-11-13 2472 !rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB | 5bb39dc956f3d4f Frederic Weisbecker 2020-11-13 2473 SEGCBLIST_KTHREAD_GP)); 314202f84ddd61e Frederic Weisbecker 2020-11-13 2474 /* 5530b1d0d6817b6 Frederic Weisbecker 2021-01-22 2475 * Lock one last time to acquire latest callback updates from kthreads 5530b1d0d6817b6 Frederic Weisbecker 2021-01-22 2476 * so we can later handle callbacks locally without locking. 314202f84ddd61e Frederic Weisbecker 2020-11-13 2477 */ 314202f84ddd61e Frederic Weisbecker 2020-11-13 2478 rcu_nocb_lock_irqsave(rdp, flags); 5530b1d0d6817b6 Frederic Weisbecker 2021-01-22 2479 /* 5530b1d0d6817b6 Frederic Weisbecker 2021-01-22 2480 * Theoretically we could set SEGCBLIST_SOFTIRQ_ONLY after the nocb 5530b1d0d6817b6 Frederic Weisbecker 2021-01-22 2481 * lock is released but how about being paranoid for once? 5530b1d0d6817b6 Frederic Weisbecker 2021-01-22 2482 */ b9ced9e1ab51ed6 Frederic Weisbecker 2020-11-13 @2483 rcu_segcblist_set_flags(cblist, SEGCBLIST_SOFTIRQ_ONLY); b9ced9e1ab51ed6 Frederic Weisbecker 2020-11-13 2484 /* b9ced9e1ab51ed6 Frederic Weisbecker 2020-11-13 2485 * With SEGCBLIST_SOFTIRQ_ONLY, we can't use 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2486 * rcu_nocb_unlock_irqrestore() anymore. b9ced9e1ab51ed6 Frederic Weisbecker 2020-11-13 2487 */ b9ced9e1ab51ed6 Frederic Weisbecker 2020-11-13 2488 raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); 314202f84ddd61e Frederic Weisbecker 2020-11-13 2489 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2490 /* Sanity check */ 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2491 WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass)); 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2492 5e04f21e88df8ce Frederic Weisbecker 2021-01-20 2493 254e11efde66ca0 Frederic Weisbecker 2020-11-13 2494 return ret; d97b078182406c0 Frederic Weisbecker 2020-11-13 2495 } d97b078182406c0 Frederic Weisbecker 2020-11-13 2496 :::::: The code at line 2483 was first introduced by commit :::::: b9ced9e1ab51ed6057ac8198fd1eeb404a32a867 rcu/nocb: Set SEGCBLIST_SOFTIRQ_ONLY at the very last stage of de-offloading :::::: TO: Frederic Weisbecker <[email protected]> :::::: CC: Paul E. McKenney <[email protected]> --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/[email protected]
.config.gz
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