>>>>> " " == kuznet <kuznet@ms2.inr.ac.ru> writes:
> Hello!
>> I forgot to add: The socket fasync lists use spinlocking in the
>> same was as RPC does, with sock_fasync() setting
>> write_lock_bh(&sk->callback_lock), and sock_def_write_space()
>> doing read_lock(&sk->callback_lock).
>>
>> So that would deadlock with the QDIO driver in the exact same
>> manner as the RPC stuff (albeit probably a lot less
>> frequently).
> Please, elaborate. I do not see any way.
Processor 1 Processor 2
(Call QDIO bottom half code)
spin_lock(&QDIO_lock);
write_lock_bh(&sk->callback_lock)
dev_kfree_skb_any()
-> kfree_skb()
<QDIO hard interrupt>
-> write_space()
->spin_lock(&QDIO_lock)
(spins...)
->read_lock(&sk->callback_lock);
(spins)
Deadlock - in exactly the same way as with the xprt code...
Cheers,
Trond
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This archive was generated by hypermail 2b29 : Fri Nov 23 2001 - 21:00:24 EST