[CRIU] [PATCH 1/2] ipc/sysctl: c/r fs.mqueue.msg_default fs.mqueue.msgsize_default

[Pavel Emelyanov]

On 06/28/2016 04:04 PM, Pavel Tikhomirov wrote:
> 
> 
> On 06/28/2016 04:03 PM, Pavel Emelyanov wrote:
>> On 06/24/2016 02:40 PM, Pavel Tikhomirov wrote:
>>> we already have 3/5 fs.mqueue.xxx sysctls so why not have all:
>>>
>>> /proc/sys/fs/mqueue/msg_default is  a read/write  file for
>>> setting/getting the default number of messages in a queue value
>>> if attr parameter of mq_open(2) is NULL. If it exceed msg_max,
>>> the default value is initialized msg_max.
>>>
>>> /proc/sys/fs/mqueue/msgsize_default is a read/write file for
>>> setting/getting the default message size value if attr parameter
>>> of mq_open(2) is NULL. If it exceed msgsize_max, the default
>>> value is initialized msgsize_max.
>>>
>>> *We have these sysctls writable in VZ7 CT.
>>
>> How about the upstream kernel?
> 
> Same, it was just a note that we need in in VZ7 too.
> 
>>
>>> @@ -322,7 +324,14 @@ static int ipc_sysctl_req(IpcVarEntry *e, int op)
>>>  		return 0;
>>>  	}
>>>
>>> -	return sysctl_op(req_mq, ARRAY_SIZE(req_mq), op, CLONE_NEWIPC);
>>> +	if (access("/proc/sys/fs/mqueue/msg_default", F_OK)) {
>>> +		/* In case the kernel is < v3.5 */
>>
>> CRIU is not supposed to work in kernels prior to 3.11. Do we really need this check?
> 
> It is not so hard to remove it, but these check can save time for custom 
> kernel users.

Please, remove. CRIU won't even get here on 3.5 kernel :)

-- Pavel