From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752648AbbF1U0n (ORCPT ); Sun, 28 Jun 2015 16:26:43 -0400 Received: from mail-la0-f48.google.com ([209.85.215.48]:36809 "EHLO mail-la0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752429AbbF1U0f (ORCPT ); Sun, 28 Jun 2015 16:26:35 -0400 MIME-Version: 1.0 In-Reply-To: <20150513134753.GA26396@e105550-lin.cambridge.arm.com> References: <1431459549-18343-1-git-send-email-morten.rasmussen@arm.com> <5552799E.2060507@nvidia.com> <20150513134753.GA26396@e105550-lin.cambridge.arm.com> Date: Sun, 28 Jun 2015 23:26:31 +0300 Message-ID: Subject: Re: [RFCv4 PATCH 00/34] sched: Energy cost model for energy-aware scheduling From: Abel Vesa To: Morten Rasmussen Cc: Sai Gurrappadi , "peterz@infradead.org" , "mingo@redhat.com" , "vincent.guittot@linaro.org" , Dietmar Eggemann , "yuyang.du@intel.com" , "preeti@linux.vnet.ibm.com" , "mturquette@linaro.org" , "rjw@rjwysocki.net" , Juri Lelli , "pang.xunlei@zte.com.cn" , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , Peter Boonstoppel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, So I tried to play around a little bit with this patchset. I did a checkout from: git://linux-arm.org/linux-power.git energy_model_rfc_v4 and then, when I tried to enable the ENERGY_AWARE from sysfs inside qemu (x86_64) and I got this: [69452.750245] BUG: unable to handle kernel paging request at ffff88009d3fb958 [69452.750245] IP: [] try_to_wake_up+0x125/0x310 [69452.750245] PGD 2155067 PUD 0 [69452.750245] Oops: 0000 [#1] SMP [69452.750245] Modules linked in: [69452.750245] CPU: 0 PID: 1007 Comm: sh Not tainted 4.1.0-rc2+ #8 [69452.750245] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 [69452.750245] task: ffff88007c9e5aa0 ti: ffff88007be0c000 task.ti: ffff88007be0c000 [69452.750245] RIP: 0010:[] [] try_to_wake_up+0x125/0x310 [69452.750245] RSP: 0000:ffff88007fc03d78 EFLAGS: 00000092 [69452.750245] RAX: 00000000ffffffff RBX: 00000000ffffffff RCX: 0000000000015a40 [69452.750245] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88007d005000 [69452.750245] RBP: ffff88007fc03dc8 R08: 0000000000000400 R09: 0000000000000000 [69452.750245] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000015a40 [69452.750245] R13: ffff88007d3fbdaa R14: 0000000000000000 R15: ffff88007d3fb660 [69452.750245] FS: 00007f8a3c9f0700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 [69452.750245] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [69452.750245] CR2: ffff88009d3fb958 CR3: 000000007c32c000 CR4: 00000000000006f0 [69452.750245] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [69452.750245] DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000 [69452.750245] Stack: [69452.750245] ffff88007fc15aa8 ffff88007c9e5b08 ffff88007fc15aa8 0000000000000046 [69452.750245] ffff88007fc03e08 ffff88007c83fe60 ffffffff81e3c8a8 ffffffff81e3c890 [69452.750245] 0000000000000000 0000000000000003 ffff88007fc03dd8 ffffffff8107bb8d [69452.750245] Call Trace: [69452.750245] [69452.750245] [] default_wake_function+0xd/0x10 [69452.750245] [] autoremove_wake_function+0x11/0x40 [69452.750245] [] __wake_up_common+0x55/0x90 [69452.750245] [] __wake_up+0x38/0x60 [69452.750245] [] rcu_gp_kthread_wake+0x42/0x50 [69452.750245] [] rcu_process_callbacks+0x2ef/0x5e0 [69452.750245] [] __do_softirq+0x9f/0x280 [69452.750245] [] irq_exit+0xa5/0xb0 [69452.750245] [] smp_apic_timer_interrupt+0x41/0x50 [69452.750245] [] apic_timer_interrupt+0x6b/0x70 [69452.750245] [69452.750245] Code: 4c 89 ff ff d0 41 83 bf f8 02 00 00 01 41 8b 5f 48 7e 16 49 8b 47 60 89 de 44 89 f1 ba 10 00 00 00 4c 89 ff ff 50 40 89 c3 89 d8 <49> 0f a3 87 00 03 00 00 19 d2 85 d2 0f 84 59 01 00 00 48 8b 15 [69452.750245] RIP [] try_to_wake_up+0x125/0x310 [69452.750245] RSP [69452.750245] CR2: ffff88009d3fb958 [69452.750245] ---[ end trace 9b4570a93c243e98 ]--- [69452.750245] Kernel panic - not syncing: Fatal exception in interrupt [69452.750245] Kernel Offset: disabled [69452.750245] ---[ end Kernel panic - not syncing: Fatal exception in interrupt and then I did a disassable from kgdb and I got this: 0xffffffff8107b8ae <+286>: callq *0x40(%rax) 0xffffffff8107b8b1 <+289>: mov %eax,%ebx 0xffffffff8107b8b3 <+291>: mov %ebx,%eax 0xffffffff8107b8b5 <+293>: bt %rax,0x300(%r15) 0xffffffff8107b8bd <+301>: sbb %edx,%edx and then I did a objdump and got this: static inline int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) { if (p->nr_cpus_allowed > 1) 7dcb: 7e 16 jle 7de3 cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); 7dcd: 49 8b 47 60 mov 0x60(%r15),%rax 7dd1: 89 de mov %ebx,%esi 7dd3: 44 89 f1 mov %r14d,%ecx 7dd6: ba 10 00 00 00 mov $0x10,%edx 7ddb: 4c 89 ff mov %r15,%rdi 7dde: ff 50 40 callq *0x40(%rax) 7de1: 89 c3 mov %eax,%ebx 7de3: 89 d8 mov %ebx,%eax 7de5: 49 0f a3 87 00 03 00 bt %rax,0x300(%r15) 7dec: 00 7ded: 19 d2 sbb %edx,%edx * Since this is common to all placement strategies, this lives here. * * [ this allows ->select_task() to simply return task_cpu(p) and * not worry about this generic constraint ] */ if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || 7def: 85 d2 test %edx,%edx I wasn't able to determine the cause from the line: 7de5: 49 0f a3 87 00 03 00 bt %rax,0x300(%r15) Finally, the question I have is: Could this happen because I'm running it from qemu? I hope all this info helps. Thanks, Abel.