On 2016/4/7 22:51, Eric Dumazet wrote:
On Thu, 2016-04-07 at 03:21 -0700, Eric Dumazet wrote:
Please do not send patches before really understanding the issue you
have.
Having a backlog of 12506206 bytes is ridiculous. Dropping packets is
absolutely fine if this ever happens.
Something is really wrong on your host, or the sender simply does not
comply with TCP protocol (not caring of receiver window at all)
Since you added a trace of truesize, please also trace skb->len
[2016-04-08 18:33:39][ 9748.726948] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:0, truesize:31992, len:17540
[2016-04-08 18:33:39][ 9748.726964] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:29326, truesize:18662,
len:10240
[2016-04-08 18:33:39][ 9748.726986] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:0, truesize:39990, len:21920
[2016-04-08 18:33:39][ 9748.727028] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:0, truesize:58652, len:32140
[2016-04-08 18:33:39][ 9748.727068] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:0, truesize:58652, len:32140
[2016-04-08 18:33:39][ 9748.727082] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:21328, truesize:5332, len:2940
[2016-04-08 18:33:39][ 9748.727310] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:0, truesize:53320, len:29220
[2016-04-08 18:33:39][ 9748.727326] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:26660, truesize:7998, len:4400
[2016-04-08 18:33:39][ 9748.727352] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:47988, truesize:58652,
len:32140
[2016-04-08 18:33:39][ 9748.727389] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:0, truesize:39990, len:21920
[2016-04-08 18:33:39][ 9748.727409] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:12607514 rmem_alloc:58652, truesize:18662,
len:10240
If I expand buffer 5 times((sndbuf+rcvbuf)*5). There are only 5M data in
backlog at most.
[2016-04-08 18:33:39][ 9748.777743] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5435954 rmem_alloc:0, truesize:55986, len:30680
[2016-04-08 18:33:39][ 9748.777762] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5457282 rmem_alloc:58652, truesize:21328,
len:11700
[2016-04-08 18:33:39][ 9748.777804] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5515934 rmem_alloc:55986, truesize:58652,
len:32140
[2016-04-08 18:33:39][ 9748.777818] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5537262 rmem_alloc:0, truesize:21328, len:11700
[2016-04-08 18:33:39][ 9748.777839] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5574586 rmem_alloc:0, truesize:37324, len:20460
[2016-04-08 18:33:39][ 9748.777854] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5601246 rmem_alloc:58652, truesize:26660,
len:14620
[2016-04-08 18:33:39][ 9748.777881] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5659898 rmem_alloc:21328, truesize:58652,
len:32140
[2016-04-08 18:33:39][ 9748.777894] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:5675894 rmem_alloc:37324, truesize:15996, len:8780
[2016-04-08 18:33:39][ 9748.778047] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:58652 rmem_alloc:0, truesize:58652, len:32140
[2016-04-08 18:33:39][ 9748.778075] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:117304 rmem_alloc:0, truesize:58652, len:32140
[2016-04-08 18:33:39][ 9748.778084] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:122636 rmem_alloc:0, truesize:5332, len:2940
[2016-04-08 18:33:39][ 9748.778109] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:175956 rmem_alloc:0, truesize:53320, len:29220
[2016-04-08 18:33:39][ 9748.778156] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:234608 rmem_alloc:0, truesize:58652, len:32140
[2016-04-08 18:33:39][ 9748.778178] TCP: rcvbuf:10485760 sndbuf:2097152
limit:12582912 backloglen:282596 rmem_alloc:58652, truesize:47988, len:26300
BTW, have you played with /proc/sys/net/ipv4/tcp_adv_win_scale ?
I expand tcp_adv_win_scale and tcp_rmem. It has no effect.
