Re: [Xenomai] [PATCH v3] nucleus: Convert intrlock to a sleeping Linux lock

[Jan Kiszka <jan.kiszka@web.de>]

On 2013-01-06 11:55, Jan Kiszka wrote:
> On 2013-01-06 11:14, Philippe Gerum wrote:
>> On 01/03/2013 03:09 PM, Jan Kiszka wrote:
>>
>>> +static struct xnvfile_lock_ops vfile_stat_lockops = {
>>> +	.get = xnintr_get_query_lock,
>>> +	.put = xnintr_put_query_lock,
>>> +};
>>> +
>>>  static struct xnvfile_snapshot stat_vfile = {
>>>  	.privsz = sizeof(struct vfile_stat_priv),
>>>  	.datasz = sizeof(struct vfile_stat_data),
>>>  	.tag = &nkpod_struct.threadlist_tag,
>>>  	.ops = &vfile_stat_ops,
>>> +	.entry = { .lockops = &vfile_stat_lockops },
>>>  };
>>
>> This would introduce a regression. stat_vfile's rewind/next handlers
>> compete with code altering the global thread queue which may run in
>> primary mode, such as xnpod_delete_thread() when deleting a kernel task.
>> So we can't use a linux lock to protect it.
> 
> The Linux lock is held around this rewind loop (which is still in
> place), and it is not protecting anything thread related, just the
> appearance and disappearance of IRQs. I fail to see a conflict, and
> there are also no I-pipe/Xenomai warnings triggered with this pattern.

Oh, now I see: The nklock is automatically taken if there are no
lockops. That needs to be done in the stat lockups as well, of course.
Will fix.

Jan

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