4.9 network not freeing memory

[Stephen Clark]

damir bikmuhametov wrote:

>On Wed, Mar 29, 2006 at 10:55:30PM -0500, Stephen Clark wrote:
>  
>
>>>Try to increase net.inet.ip.intr_queue_maxlen and monitor
>>>net.inet.ip.intr_queue_drops.
>>>      
>>>
>>Increasing net.inet.ip.intr_queue_maxlen to 400 seems to have fixed the 
>>problem.
>>    
>>
>
>Could you please report this to the list after some testing?
>
>Thanks.
>
>  
>
Do you know if the queue_maxlen is exceeded do the mbufs get lost? It
sort of seems that is
what happens.

This is after a test where I was increment queue_maxlen til queue_drops
were not increasing.
$ sysctl net.inet.ip.intr_queue_drops
net.inet.ip.intr_queue_drops: 27444
X10001:~

At this point the network after my test the network is pretty much quiet.
But there are still mbufs allocated for data??
$ netstat -m
689/5504/131072 mbufs in use (current/peak/max):
         689 mbufs allocated to data
265/4958/32768 mbuf clusters in use (current/peak/max)
11292 Kbytes allocated to network (11% of mb_map in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines


After a reboot:
X10001:~
$ sysctl net.inet.ip.intr_queue_drops
net.inet.ip.intr_queue_drops: 0
X10001:~
$ netstat -m
2/416/131072 mbufs in use (current/peak/max):
         2 mbufs allocated to data
0/44/32768 mbuf clusters in use (current/peak/max)
192 Kbytes allocated to network (0% of mb_map in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines


This after a reboot and another test with queue_maxlen=400
Note there are only 3 mbufs allocated to data.

sysctl net.inet.ip.intr_queue_drops
net.inet.ip.intr_queue_drops: 0
X10001:~
$ netstat -m
3/416/131072 mbufs in use (current/peak/max):
         3 mbufs allocated to data
0/44/32768 mbuf clusters in use (current/peak/max)
192 Kbytes allocated to network (0% of mb_map in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines


Is there some way to see what the current queue length is? Like the
queue drops.

What do you think?

Regards,
Steve