tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git softirq head: 383be10736ef5b48c0914e89c6e0a61b78623dda commit: 1e60e1b199c141e5d1757743e19310d2ba5fecde [7/20] tasklets: Prevent tasklet_unlock_spin_wait() deadlock on RT config: x86_64-rhel-7.6-kselftests (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git/commit/?id... git remote add tglx-devel https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git git fetch --no-tags tglx-devel softirq git checkout 1e60e1b199c141e5d1757743e19310d2ba5fecde # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): 624 | void tasklet_unlock_spin_wait(struct tasklet_struct *t) | ^~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/kernel_stat.h:9, from kernel/softirq.c:13: include/linux/interrupt.h:670:20: note: previous definition of 'tasklet_unlock_spin_wait' was here 670 | static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) | ^~~~~~~~~~~~~~~~~~~~~~~~ vim +/tasklet_unlock_spin_wait +624 kernel/softirq.c 618 619 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT) 620 /* 621 * Do not use in new code. There is no real reason to invoke this from 622 * atomic contexts. 623 */ 625 { 626 while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { 627 if (IS_ENABLED(CONFIG_PREEMPT_RT)) { 628 /* 629 * Prevent a live lock when current preempted soft 630 * interrupt processing or prevents ksoftirqd from 631 * running. If the tasklet runs on a different CPU 632 * then this has no effect other than doing the BH 633 * disable/enable dance for nothing. 634 */ 635 local_bh_disable(); 636 local_bh_enable(); 637 } else { 638 cpu_relax(); 639 } 640 } 641 } 642 EXPORT_SYMBOL(tasklet_unlock_spin_wait); 643 #endif 644 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org