[CRIU] [PATCH v2 06/15] unix: Add sender_ino of packets and socket

[Kirill Tkhai]

On 31.05.2016 14:02, Pavel Emelyanov wrote:
> On 05/30/2016 03:30 PM, Kirill Tkhai wrote:
>>
>>
>> On 30.05.2016 14:40, Pavel Emelyanov wrote:
>>> On 05/27/2016 04:06 PM, Kirill Tkhai wrote:
>>>> Add optional field "sender_ino" to packet and socket proto.
>>>>
>>>> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>>>> ---
>>>>  images/sk-packet.proto |    1 +
>>>>  images/sk-unix.proto   |    2 ++
>>>>  2 files changed, 3 insertions(+)
>>>>
>>>> diff --git a/images/sk-packet.proto b/images/sk-packet.proto
>>>> index 10ef5c9..2e1c8b3 100644
>>>> --- a/images/sk-packet.proto
>>>> +++ b/images/sk-packet.proto
>>>> @@ -1,4 +1,5 @@
>>>>  message sk_packet_entry {
>>>>  	required uint32		id_for		= 1;
>>>>  	required uint32		length		= 2;
>>>> +	optional uint32		sender_ino	= 3;
>>>
>>> This is understood.
>>>
>>>>  }
>>>> diff --git a/images/sk-unix.proto b/images/sk-unix.proto
>>>> index aa2bcf7..7b71ebf 100644
>>>> --- a/images/sk-unix.proto
>>>> +++ b/images/sk-unix.proto
>>>> @@ -45,4 +45,6 @@ message unix_sk_entry {
>>>>  	 * Relative socket name may have prefix.
>>>>  	 */
>>>>  	optional string			name_dir	= 14;
>>>> +
>>>> +	optional uint32			sender_ino	= 15;
>>>
>>> Why do you need this new number on socket entry?
>>
>> This allows to understand that a DGRAM socket is not a promiscuous.
>> If so, we may set a sender as our queuer (see sk_queuer()).
>>
>> Otherwise, we would have to do additional work on restore. We would
>> have to scan skb queue to understand if it's promiscuous.
>>
>> Using unix_sk_entry::sender_ino, we easily mark the most sockets as
>> "having queuer", and skip them on "resolve senders" stage.
>> See resolve_unix_peers() changes.
> 
> OK. From my perspective you don't need this in image. During resolve_unix_peers()
> we scan all the sockets, you can add analysis of the packets and find out
> whether the socket is no-queuer or not.

I think this trick may speed-up restore in some way. If you are worrying about
using of space for that, I can add USK_HAS_SENDER flag instead. Is it OK for you?