On Mon, Feb 26, 2018 at 04:16:19PM +0100, Geert Uytterhoeven wrote: > On Mon, Feb 5, 2018 at 5:42 PM, Mark Rutland <mark.rutland@xxxxxxx> wrote: > > To support ACPI systems, we need to request IRQs before CPUs are > > hotplugged, and thus we need to request IRQs before we know their > > associated PMU. > > > > This is problematic if a PMU IRQ is pending out of reset, as it may be > > taken before we know the PMU, and thus the IRQ handler won't be able to > > handle it, leaving it screaming. > > > > To avoid such problems, lets request all IRQs in a disabled state, and > > explicitly enable/disable them at hotplug time, when we're sure the PMU > > has been probed. > > > > Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> > > This is now commit 6de3f79112cc26bf in v4.16-rc3, and causes a BUG during > CPU offlining (e.g. during system suspend, or during boot with > CONFIG_ARM_PSCI_CHECKER=y). > > With CONFIG_ARM_PSCI_CHECKER=y: > > psci_checker: PSCI checker started using 6 CPUs > psci_checker: Starting hotplug tests > psci_checker: Trying to turn off and on again all CPUs > BUG: sleeping function called from invalid context at kernel/irq/manage.c:112 > in_atomic(): 1, irqs_disabled(): 128, pid: 15, name: migration/1 > no locks held by migration/1/15. > irq event stamp: 192 > hardirqs last enabled at (191): [<00000000803c2507>] > _raw_spin_unlock_irq+0x2c/0x4c > hardirqs last disabled at (192): [<000000007f57ad28>] multi_cpu_stop+0x9c/0x140 > softirqs last enabled at (0): [<0000000004ee1b58>] > copy_process.isra.77.part.78+0x43c/0x1504 > softirqs last disabled at (0): [< (null)>] (null) > CPU: 1 PID: 15 Comm: migration/1 Not tainted 4.16.0-rc3-salvator-x #1651 > Hardware name: Renesas Salvator-X board based on r8a7796 (DT) > Call trace: > dump_backtrace+0x0/0x140 > show_stack+0x14/0x1c > dump_stack+0xb4/0xf0 > ___might_sleep+0x1fc/0x218 > __might_sleep+0x70/0x80 > synchronize_irq+0x40/0xa8 > disable_irq+0x20/0x2c Given that these things are CPU-affine, I reckon this should be disable_irq_nosync. Mark? Will --->8 diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 0c2ed11c0603..f63db346c219 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -638,7 +638,7 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node) if (irq_is_percpu_devid(irq)) disable_percpu_irq(irq); else - disable_irq(irq); + disable_irq_nosync(irq); } per_cpu(cpu_armpmu, cpu) = NULL;
