On 10/12/2015 11:16 AM, Thomas Gleixner wrote:
> On Fri, 9 Oct 2015, Grygorii Strashko wrote:
>> 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
>
>> It looks like this backtrace was introduces by
>>
>> commit 91df05da13a6c6c358e71182e80f19f3c48d1615
>> 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))) {
>
> Your patch is white space damaged ....
>
>> 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.
>
> It is. Picking it up for the next release
>
Thanks & Sorry. I've not expected this diff/hack to be applied as patch :(
--
regards,
-grygorii
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