On Mon, Apr 30, 2018 at 9:38 AM Steven Rostedt <[email protected]> wrote:
> On Thu, 26 Apr 2018 21:11:00 -0700 > Joel Fernandes <[email protected]> wrote: > > I'm able to reproduce a lockdep splat when CONFIG_PROVE_LOCKING=y and > > CONFIG_PREEMPTIRQ_EVENTS=y. > > > > $ echo 1 > /d/tracing/events/preemptirq/preempt_enable/enable > > --- > > [ 26.112609] DEBUG_LOCKS_WARN_ON(current->softirqs_enabled) > > [ 26.112636] WARNING: CPU: 0 PID: 118 at kernel/locking/lockdep.c:3854 > > [...] > > [ 26.144229] Call Trace: > > [ 26.144926] <IRQ> > > [ 26.145506] lock_acquire+0x55/0x1b0 > > [ 26.146499] ? __do_softirq+0x46f/0x4d9 > > [ 26.147571] ? __do_softirq+0x46f/0x4d9 > > [ 26.148646] trace_preempt_on+0x8f/0x240 > > [ 26.149744] ? trace_preempt_on+0x4d/0x240 > > [ 26.150862] ? __do_softirq+0x46f/0x4d9 > > [ 26.151930] preempt_count_sub+0x18a/0x1a0 > > [ 26.152985] __do_softirq+0x46f/0x4d9 > > [ 26.153937] irq_exit+0x68/0xe0 > > [ 26.154755] smp_apic_timer_interrupt+0x271/0x280 > > [ 26.156056] apic_timer_interrupt+0xf/0x20 > > [ 26.157105] </IRQ> > I'm not able to trigger this. Is there more to it? No that should be it. I have a 100% repro on v4.16. I will try on a newer kernel and let you know. thanks, - Joel
