[4.1.3-rt8] [report][cpuhotplug] BUG: spinlock bad magic on CPU#0, sh/137
From: Grygorii Strashko <grygorii.strashko@ti.com>
Date: 2015-10-09 14:25:57
Hi All,
I can constantly see below error report with 4.1 RT-kernel on TI ARM dra7-evm
if I'm trying to unplug cpu1:
[ 57.737589] CPU1: shutdown
[ 57.767537] BUG: spinlock bad magic on CPU#0, sh/137
[ 57.767546] lock: 0xee994730, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[ 57.767552] CPU: 0 PID: 137 Comm: sh Not tainted 4.1.10-rt8-01700-g2c38702-dirty #55
[ 57.767555] Hardware name: Generic DRA74X (Flattened Device Tree)
[ 57.767568] [<c001acd0>] (unwind_backtrace) from [<c001534c>] (show_stack+0x20/0x24)
[ 57.767579] [<c001534c>] (show_stack) from [<c075560c>] (dump_stack+0x84/0xa0)
[ 57.767593] [<c075560c>] (dump_stack) from [<c00aca48>] (spin_dump+0x84/0xac)
[ 57.767603] [<c00aca48>] (spin_dump) from [<c00acaa4>] (spin_bug+0x34/0x38)
[ 57.767614] [<c00acaa4>] (spin_bug) from [<c00acc10>] (do_raw_spin_lock+0x168/0x1c0)
[ 57.767624] [<c00acc10>] (do_raw_spin_lock) from [<c075b4cc>] (_raw_spin_lock+0x4c/0x54)
[ 57.767631] [<c075b4cc>] (_raw_spin_lock) from [<c07599fc>] (rt_spin_lock_slowlock+0x5c/0x374)
[ 57.767638] [<c07599fc>] (rt_spin_lock_slowlock) from [<c075bcf4>] (rt_spin_lock+0x38/0x70)
[ 57.767649] [<c075bcf4>] (rt_spin_lock) from [<c06333c0>] (skb_dequeue+0x28/0x7c)
[ 57.767662] [<c06333c0>] (skb_dequeue) from [<c06476ec>] (dev_cpu_callback+0x1b8/0x240)
[ 57.767673] [<c06476ec>] (dev_cpu_callback) from [<c007566c>] (notifier_call_chain+0x3c/0xb4)
[ 57.767683] [<c007566c>] (notifier_call_chain) from [<c0075708>] (__raw_notifier_call_chain+0x24/0x2c)
[ 57.767692] [<c0075708>] (__raw_notifier_call_chain) from [<c004f2a4>] (cpu_notify+0x34/0x50)
[ 57.767699] [<c004f2a4>] (cpu_notify) from [<c004f65c>] (cpu_notify_nofail+0x18/0x24)
[ 57.767707] [<c004f65c>] (cpu_notify_nofail) from [<c074f304>] (_cpu_down+0x3e8/0x55c)
[ 57.767715] [<c074f304>] (_cpu_down) from [<c004ff74>] (disable_nonboot_cpus+0x118/0x5dc)
[ 57.767722] [<c004ff74>] (disable_nonboot_cpus) from [<c00b091c>] (suspend_enter+0x2c4/0xd18)
[ 57.767730] [<c00b091c>] (suspend_enter) from [<c00b1454>] (suspend_devices_and_enter+0xe4/0x65c)
[ 57.767737] [<c00b1454>] (suspend_devices_and_enter) from [<c00b208c>] (enter_state+0x6c0/0x1050)
[ 57.767744] [<c00b208c>] (enter_state) from [<c00b2a40>] (pm_suspend+0x24/0x84)
[ 57.767751] [<c00b2a40>] (pm_suspend) from [<c00af460>] (state_store+0x74/0xc8)
[ 57.767760] [<c00af460>] (state_store) from [<c040a660>] (kobj_attr_store+0x1c/0x28)
[ 57.767771] [<c040a660>] (kobj_attr_store) from [<c024563c>] (sysfs_kf_write+0x5c/0x60)
[ 57.767781] [<c024563c>] (sysfs_kf_write) from [<c0244720>] (kernfs_fop_write+0xc8/0x1ac)
[ 57.767792] [<c0244720>] (kernfs_fop_write) from [<c01c3974>] (__vfs_write+0x38/0xec)
[ 57.767801] [<c01c3974>] (__vfs_write) from [<c01c4290>] (vfs_write+0xa0/0x174)
[ 57.767811] [<c01c4290>] (vfs_write) from [<c01c4b30>] (SyS_write+0x54/0xb0)
[ 57.767822] [<c01c4b30>] (SyS_write) from [<c0010b20>] (ret_fast_syscall+0x0/0x54)
[ 57.768224] Powerdomain (l3init_pwrdm) didn't enter target state 1
I'm working with TI RT-kernel:
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git
branch: ti-rt-linux-4.1.y
It looks like this backtrace was introduces by
commit 91df05da13a6c6c358e71182e80f19f3c48d1615
Author: Thomas Gleixner [off-list ref]
Date: Tue Jul 12 15:38:34 2011 +0200
net: Use skbufhead with raw lock
I see the potential fix for this issue as below:
index 4969c0d..f8c23de 100644--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -7217,7 +7217,7 @@ static int dev_cpu_callback(struct notifier_block *nfb, netif_rx_ni(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx_ni(skb); input_queue_head_incr(oldsd); }
input_pkt_queue is per-cpu queue and at this moment cpu is dead already, so no one should touch it. But I'm not sure if my assumption is correct. -- regards, -grygorii