tree: feng/pcache_cleanup head: a20ca1d06794ad410f289251bf9e9abb781e9008 commit: 85ec1a159459a96dc01e02f957e9ab98d6b0cf87 [51/54] watchdog: warn on soft lockup config: h8300-randconfig-a001-20200412 (attached as .config) compiler: h8300-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 85ec1a159459a96dc01e02f957e9ab98d6b0cf87 # save the attached .config to linux build tree GCC_VERSION=9.3.0 make.cross ARCH=h8300 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): h8300-linux-ld: kernel/watchdog.o: in function `watchdog_timer_fn': vim +447 kernel/watchdog.c 360 361 /* watchdog kicker functions */ 362 static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) 363 { 364 unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts); 365 struct pt_regs *regs = get_irq_regs(); 366 int duration; 367 int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace; 368 369 if (!watchdog_enabled) 370 return HRTIMER_NORESTART; 371 372 /* kick the hardlockup detector */ 373 watchdog_interrupt_count(); 374 375 /* kick the softlockup detector */ 376 if (completion_done(this_cpu_ptr(&softlockup_completion))) { 377 reinit_completion(this_cpu_ptr(&softlockup_completion)); 378 stop_one_cpu_nowait(smp_processor_id(), 379 softlockup_fn, NULL, 380 this_cpu_ptr(&softlockup_stop_work)); 381 } 382 383 /* .. and repeat */ 384 hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period)); 385 386 if (touch_ts == 0) { 387 if (unlikely(__this_cpu_read(softlockup_touch_sync))) { 388 /* 389 * If the time stamp was touched atomically 390 * make sure the scheduler tick is up to date. 391 */ 392 __this_cpu_write(softlockup_touch_sync, false); 393 sched_clock_tick(); 394 } 395 396 /* Clear the guest paused flag on watchdog reset */ 397 kvm_check_and_clear_guest_paused(); 398 __touch_watchdog(); 399 return HRTIMER_RESTART; 400 } 401 402 /* check for a softlockup 403 * This is done by making sure a high priority task is 404 * being scheduled. The task touches the watchdog to 405 * indicate it is getting cpu time. If it hasn't then 406 * this is a good indication some task is hogging the cpu 407 */ 408 duration = is_softlockup(touch_ts); 409 if (unlikely(duration)) { 410 /* 411 * If a virtual machine is stopped by the host it can look to 412 * the watchdog like a soft lockup, check to see if the host 413 * stopped the vm before we issue the warning 414 */ 415 if (kvm_check_and_clear_guest_paused()) 416 return HRTIMER_RESTART; 417 418 /* only warn once */ 419 if (__this_cpu_read(soft_watchdog_warn) == true) { 420 /* 421 * When multiple processes are causing softlockups the 422 * softlockup detector only warns on the first one 423 * because the code relies on a full quiet cycle to 424 * re-arm. The second process prevents the quiet cycle 425 * and never gets reported. Use task pointers to detect 426 * this. 427 */ 428 if (__this_cpu_read(softlockup_task_ptr_saved) != 429 current) { 430 __this_cpu_write(soft_watchdog_warn, false); 431 __touch_watchdog(); 432 } 433 return HRTIMER_RESTART; 434 } 435 436 if (softlockup_all_cpu_backtrace) { 437 /* Prevent multiple soft-lockup reports if one cpu is already 438 * engaged in dumping cpu back traces 439 */ 440 if (test_and_set_bit(0, &soft_lockup_nmi_warn)) { 441 /* Someone else will report us. Let's give up */ 442 __this_cpu_write(soft_watchdog_warn, true); 443 return HRTIMER_RESTART; 444 } 445 } 446 448 449 pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", 450 smp_processor_id(), duration, 451 current->comm, task_pid_nr(current)); 452 __this_cpu_write(softlockup_task_ptr_saved, current); 453 print_modules(); 454 print_irqtrace_events(current); 455 if (regs) 456 show_regs(regs); 457 else 458 dump_stack(); 459 460 if (softlockup_all_cpu_backtrace) { 461 /* Avoid generating two back traces for current 462 * given that one is already made above 463 */ 464 trigger_allbutself_cpu_backtrace(); 465 466 clear_bit(0, &soft_lockup_nmi_warn); 467 /* Barrier to sync with other cpus */ 468 smp_mb__after_atomic(); 469 } 470 471 add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK); 472 if (softlockup_panic) 473 panic("softlockup: hung tasks"); 474 __this_cpu_write(soft_watchdog_warn, true); 475 } else 476 __this_cpu_write(soft_watchdog_warn, false); 477 478 return HRTIMER_RESTART; 479 } 480 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org