On 03/31/2015 11:07 AM, Peter Zijlstra wrote: >>> @@ -1781,7 +1781,7 @@ schedule_hrtimeout_range_clock(ktime_t * >>> > > t.task = NULL; >>> > > >>> > > if (likely(t.task)) >>> > > - schedule(); >>> > > + freezable_schedule(); >>> > > >>> > > hrtimer_cancel(&t.timer); >>> > > destroy_hrtimer_on_stack(&t.timer); > Not a single word on why this would be correct. At the very least show > us you've thought about it.
It's not correct. [ 0.634248] ===================================== [ 0.635011] [ BUG: swapper/0/1 still has locks held! ] [ 0.635566] 4.0.0-rc6-next-20150402-sasha-00038-g3637da5 #2121 Not tainted [ 0.636009] ------------------------------------- [ 0.636508] 2 locks held by swapper/0/1: [ 0.637008] #0: (cpu_hotplug.lock){.+.+.+}, at: get_online_cpus (kernel/cpu.c:96) [ 0.638009] #1: (smpboot_threads_lock){+.+.+.}, at: smpboot_register_percpu_thread (kernel/smpboot.c:286) [ 0.639013] Mutex: counter: 0 owner: swapper/0 [ 0.640010] [ 0.640010] stack backtrace: [ 0.640543] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc6-next-20150402-sasha-00038-g3637da5 #2121 [ 0.641012] ffff8809e2748000 00000000d284eea5 ffff88004e8df948 ffffffff9dabb4a2 [ 0.642622] 0000000000000000 ffff8809e2748000 ffff88004e8df968 ffffffff932e848d [ 0.643627] ffff88004e8df9a8 ffff88004e8dfa48 ffff88004e8dfa78 ffffffff9db2e57c [ 0.644624] Call Trace: [ 0.645021] dump_stack (lib/dump_stack.c:52) [ 0.645644] debug_check_no_locks_held (kernel/locking/lockdep.c:4178) [ 0.646019] schedule_hrtimeout_range_clock (include/linux/freezer.h:56 include/linux/freezer.h:66 include/linux/freezer.h:127 include/linux/freezer.h:172 kernel/time/hrtimer.c:1784) [ 0.647017] ? hrtimer_nanosleep_restart (kernel/time/hrtimer.c:1754) [ 0.648015] ? get_lock_stats (kernel/locking/lockdep.c:249) [ 0.648702] ? hrtimer_get_res (kernel/time/hrtimer.c:1472) [ 0.649016] ? schedule_hrtimeout_range_clock (kernel/time/hrtimer.c:1780) [ 0.650020] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63) [ 0.651016] schedule_hrtimeout (kernel/time/hrtimer.c:1856) [ 0.652015] wait_task_inactive (kernel/sched/core.c:1260 (discriminator 1)) [ 0.652656] ? migrate_swap (kernel/sched/core.c:1184) [ 0.653015] ? out_of_line_wait_on_atomic_t (kernel/sched/completion.c:121) [ 0.654016] ? wake_up_state (kernel/sched/core.c:2973) [ 0.654614] __kthread_bind (kernel/kthread.c:331) [ 0.655015] __kthread_unpark (kernel/kthread.c:394) [ 0.655622] kthread_unpark (kernel/kthread.c:413) [ 0.656014] ? ftrace_define_fields_softirq (kernel/softirq.c:755) [ 0.657014] smpboot_unpark_thread.isra.0 (kernel/smpboot.c:227) [ 0.657725] smpboot_register_percpu_thread (kernel/smpboot.c:286) [ 0.658013] ? ftrace_define_fields_softirq (kernel/softirq.c:755) [ 0.659015] ? ftrace_define_fields_softirq (kernel/softirq.c:755) [ 0.660013] spawn_ksoftirqd (kernel/softirq.c:758) [ 0.660609] do_one_initcall (init/main.c:787) [ 0.661014] ? try_to_run_init_process (init/main.c:776) [ 0.662017] ? print_cpu_info (arch/x86/kernel/cpu/common.c:1140 arch/x86/kernel/cpu/common.c:1135) [ 0.662638] ? native_smp_prepare_cpus (arch/x86/kernel/smpboot.c:1167) [ 0.663016] kernel_init_freeable (init/main.c:888 init/main.c:994) [ 0.664014] ? start_kernel (init/main.c:972) [ 0.664619] ? finish_task_switch (include/linux/tick.h:125 kernel/sched/core.c:2248) [ 0.665013] ? finish_task_switch (kernel/sched/sched.h:1077 kernel/sched/core.c:2230) [ 0.666019] ? rest_init (init/main.c:927) [ 0.666597] kernel_init (init/main.c:932) [ 0.667015] ? rest_init (init/main.c:927) [ 0.667593] ret_from_fork (arch/x86/kernel/entry_64.S:535) [ 0.668014] ? rest_init (init/main.c:927) Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/