On Mon, Jul 08, 2013 at 06:50:23PM +0200, Peter Zijlstra wrote: > > [ 324.983534] ------------[ cut here ]------------ > [ 324.984420] WARNING: at /usr/src/linux-2.6/kernel/events/core.c:1953 __perf_event_enable+0x187/0x190() > [ 324.984420] Modules linked in: > [ 324.984420] CPU: 19 PID: 2715 Comm: nmi_bug_snb Not tainted 3.10.0+ #246 > [ 324.984420] Hardware name: Supermicro X8DTN/X8DTN, BIOS 4.6.3 01/08/2010 > [ 324.984420] 0000000000000009 ffff88043fce3ec8 ffffffff8160ea0b ffff88043fce3f00 > [ 324.984420] ffffffff81080ff0 ffff8802314fdc00 ffff880231a8f800 ffff88043fcf7860 > [ 324.984420] 0000000000000286 ffff880231a8f800 ffff88043fce3f10 ffffffff8108103a > [ 324.984420] Call Trace: > [ 324.984420] <IRQ> [<ffffffff8160ea0b>] dump_stack+0x19/0x1b > [ 324.984420] [<ffffffff81080ff0>] warn_slowpath_common+0x70/0xa0 > [ 324.984420] [<ffffffff8108103a>] warn_slowpath_null+0x1a/0x20 > [ 324.984420] [<ffffffff81134437>] __perf_event_enable+0x187/0x190 > [ 324.984420] [<ffffffff81130030>] remote_function+0x40/0x50 > [ 324.984420] [<ffffffff810e51de>] generic_smp_call_function_single_interrupt+0xbe/0x130 > [ 324.984420] [<ffffffff81066a47>] smp_call_function_single_interrupt+0x27/0x40 > [ 324.984420] [<ffffffff8161fd2f>] call_function_single_interrupt+0x6f/0x80 > [ 324.984420] <EOI> [<ffffffff816161a1>] ? _raw_spin_unlock_irqrestore+0x41/0x70 > [ 324.984420] [<ffffffff8113799d>] perf_event_exit_task+0x14d/0x210 > [ 324.984420] [<ffffffff810acd04>] ? switch_task_namespaces+0x24/0x60 > [ 324.984420] [<ffffffff81086946>] do_exit+0x2b6/0xa40 > [ 324.984420] [<ffffffff8161615c>] ? _raw_spin_unlock_irq+0x2c/0x30 > [ 324.984420] [<ffffffff81087279>] do_group_exit+0x49/0xc0 > [ 324.984420] [<ffffffff81096854>] get_signal_to_deliver+0x254/0x620 > [ 324.984420] [<ffffffff81043057>] do_signal+0x57/0x5a0 > [ 324.984420] [<ffffffff8161a164>] ? __do_page_fault+0x2a4/0x4e0 > [ 324.984420] [<ffffffff8161665c>] ? retint_restore_args+0xe/0xe > [ 324.984420] [<ffffffff816166cd>] ? retint_signal+0x11/0x84 > [ 324.984420] [<ffffffff81043605>] do_notify_resume+0x65/0x80 > [ 324.984420] [<ffffffff81616702>] retint_signal+0x46/0x84 > [ 324.984420] ---[ end trace 442ec2f04db3771a ]--- OK, this looks like an unrelated issue. Still wants fixing though. It looks like we get an IPI from perf_event_enable() right after we release child_ctx->lock in perf_event_exit_task_context(). I don't see what we could do here other than write a comment and remove the WARN. It seems a valid, albeit, unlikely scenario. -- To unsubscribe from this list: send the line "unsubscribe trinity" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
