On Wed, Jun 25, 2014 at 11:36:57AM +0200, Peter Zijlstra wrote: > On Wed, Jun 25, 2014 at 12:07:05PM +0530, Srivatsa S. Bhat wrote: > > I don't think irqs_disabled() is the problematic condition, since > > hotplug_cfg() invokes irq_work_run() from CPU_DYING context (which has > > irqs disabled). I guess you meant to remove the in_irq() check inside > > irq_work_run() instead? > > Yes, clearly I should not get up at 6am.. :-) Let me go do a new one. --- Subject: irq_work: Remove BUG_ON in irq_work_run() From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Date: Wed Jun 25 07:13:07 CEST 2014 Because of a collision with 8d056c48e486 ("CPU hotplug, smp: flush any pending IPI callbacks before CPU offline"), which ends up calling hotplug_cfd()->flush_smp_call_function_queue()->irq_work_run(), which is not from IRQ context. Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Reported-by: Stephen Warren <swarren@xxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/n/tip-busatzs2gvz4v62258agipuf@xxxxxxxxxxxxxx --- kernel/irq_work.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) Index: linux-2.6/kernel/irq_work.c =================================================================== --- linux-2.6.orig/kernel/irq_work.c +++ linux-2.6/kernel/irq_work.c @@ -160,21 +160,11 @@ static void irq_work_run_list(struct lli } } -static void __irq_work_run(void) +static void irq_work_run(void) { irq_work_run_list(&__get_cpu_var(raised_list)); irq_work_run_list(&__get_cpu_var(lazy_list)); } - -/* - * Run the irq_work entries on this cpu. Requires to be ran from hardirq - * context with local IRQs disabled. - */ -void irq_work_run(void) -{ - BUG_ON(!in_irq()); - __irq_work_run(); -} EXPORT_SYMBOL_GPL(irq_work_run); /* -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html