Re: [PATCH 1/3] colo-compare: return -1 if no packet is queued

[Li Zhijian <lizhijian@cn.fujitsu.com>]

On 9/23/20 9:41 AM, Zhang, Chen wrote:
>
>> -----Original Message-----
>> From: Li Zhijian <lizhijian@cn.fujitsu.com>
>> Sent: Tuesday, September 22, 2020 5:55 PM
>> To: Zhang, Chen <chen.zhang@intel.com>; jasowang@redhat.com
>> Cc: qemu-devel@nongnu.org; Li Zhijian <lizhijian@cn.fujitsu.com>
>> Subject: [PATCH 1/3] colo-compare: return -1 if no packet is queued
>>
>> Return 0 will trigger a packet comparison
>>
> Yes, we need active trigger a checkpoint to flush all the queued packets here.
Previously, no new checkpoint will be triggered since no new packet is queued though colo_compare_connection() is called.
actually we should send a notify to colo frame immediately, no need to compare them any more in order to less latency.

diff --git a/net/colo-compare.c b/net/colo-compare.c
index 3a45d64175..23092e4496 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -285,10 +285,13 @@ static int packet_enqueue(CompareState *s, int mode, Connection **con)
      }

      if (!ret) {
+        /* queue is too long, do a checkpoint to release all queued packets */
+        colo_compare_inconsistency_notify(s);
          trace_colo_compare_drop_packet(colo_mode[mode],
              "queue size too big, drop packet");
          packet_destroy(pkt, NULL);
          pkt = NULL;
+        return -1;
      }

      *con = conn;


> Otherwise, we should drop all the packet after this time still next checkpoint.
> So, I think original logic is a better choice.
>
> Thanks
> Zhang Chen
>
>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>> ---
>>   net/colo-compare.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/net/colo-compare.c b/net/colo-compare.c index
>> 3a45d64175..039b515611 100644
>> --- a/net/colo-compare.c
>> +++ b/net/colo-compare.c
>> @@ -289,6 +289,7 @@ static int packet_enqueue(CompareState *s, int
>> mode, Connection **con)
>>               "queue size too big, drop packet");
>>           packet_destroy(pkt, NULL);
>>           pkt = NULL;
>> +        return -1;
>>       }
>>
>>       *con = conn;
>> --
>> 2.28.0
>>
>>
>
>