Re: spinlock recursion in aio_complete()

[Bart Van Assche <bvanassche@acm.org>]

On 5/22/23 13:51, Helge Deller wrote:
> On 5/22/23 21:28, Bart Van Assche wrote:
>> On 5/20/23 22:43, Helge Deller wrote:
>>> On a single-CPU parisc64 machine I face the spinlock recursion below.
>>> Happens reproduceably directly at bootup since kernel 6.2 (and ~ 6.1.5).
>>> Kernel is built for SMP. Same kernel binary works nicely on machines with more than
>>> one CPU, but stops on UP machines.
>>> Any idea or patch I could try?
>>
>> How about performing one or more of the following actions?
>> * Translating aio_complete+0x68 into a line number.
> 
> It hangs in fs/aio.c:1128, function aio_complete(), in this call:
>      spin_lock_irqsave(&ctx->completion_lock, flags);

All code that I found and that obtains ctx->completion_lock disables IRQs.
It is not clear to me how this spinlock can be locked recursively? Is it
sure that the "spinlock recursion" report is correct?

Thanks,

Bart.