We recentlty discovered a call path which takes a mutex from the low level secondary CPU bringup code and wondered why this was not caught by might_sleep().
The reason is that both debug facilities depend on system_state == SYSTEM_RUNNING, which is set after init memory is freed. That means that the SMP bootup and the builtin driver initialization is not covered by these checks at all. The patch series addresses this by adding two intermediate states. might_sleep() debugging is enabled right when scheduling starts, i.e. the boot CPU idle task schedules the first time. smp_processor_id() debugging is enabled right before SMP bringup happens. Thanks, tglx ---- arch/arm/kernel/smp.c | 3 +-- arch/metag/kernel/smp.c | 3 +-- arch/x86/kernel/smpboot.c | 2 +- b/arch/arm64/kernel/smp.c | 3 +-- b/arch/powerpc/kernel/smp.c | 2 +- drivers/acpi/pci_root.c | 2 +- drivers/base/node.c | 2 +- drivers/cpufreq/pasemi-cpufreq.c | 2 +- drivers/iommu/intel-iommu.c | 4 ++-- drivers/iommu/of_iommu.c | 2 +- drivers/xen/manage.c | 2 ++ include/linux/kernel.h | 2 ++ init/main.c | 12 ++++++++++-- kernel/async.c | 8 ++++---- kernel/extable.c | 2 +- kernel/printk/printk.c | 2 +- kernel/sched/core.c | 4 +++- lib/smp_processor_id.c | 2 +- mm/vmscan.c | 2 +- 19 files changed, 36 insertions(+), 25 deletions(-)