tuning for high connection rates

[Philipp Wuensche]

Mike Tancsa wrote:
> At 07:14 PM 12/4/2007, Philipp Wuensche wrote:
> 
>> The debug output of em0 looks like this:
>>
>> em0: CTRL = 0x40140248 RCTL = 0x8002
>> em0: Packet buffer = Tx=20k Rx=12k
>> em0: Flow control watermarks high = 10240 low = 8740
>> em0: tx_int_delay = 66, tx_abs_int_delay = 66
>> em0: rx_int_delay = 32, rx_abs_int_delay = 66
>> em0: fifo workaround = 0, fifo_reset_count = 0
>> em0: hw tdh = 183, hw tdt = 183
>> em0: hw rdh = 139, hw rdt = 139
>> em0: Num Tx descriptors avail = 223
>> em0: Tx Descriptors not avail1 = 6225
>> em0: Tx Descriptors not avail2 = 3
>> em0: Std mbuf failed = 0
>> em0: Std mbuf cluster failed = 0
>> em0: Driver dropped packets = 0
>> em0: Driver tx dma failure in encap = 0
> 
> If you do a
> sysctl -w dev.em.0.stats=1
> 
> It will spit the nic stats to syslog.  What are the results ? 

em0: Excessive collisions = 0
em0: Sequence errors = 0
em0: Defer count = 0
em0: Missed Packets = 12876719
em0: Receive No Buffers = 5950326
em0: Receive Length Errors = 0
em0: Receive errors = 0
em0: Crc errors = 0
em0: Alignment errors = 0
em0: Collision/Carrier extension errors = 0
em0: RX overruns = 56256
em0: watchdog timeouts = 0
em0: XON Rcvd = 0
em0: XON Xmtd = 0
em0: XOFF Rcvd = 0
em0: XOFF Xmtd = 0
em0: Good Packets Rcvd = 3384408375
em0: Good Packets Xmtd = 2657550034
em0: TSO Contexts Xmtd = 6925441
em0: TSO Contexts Failed = 0


> Also,
> what does ifconfig em0 look like (i.e. what options do you have set,
> speed etc)

Its on a 100Mbit/s switch, we haven't changed the options:

em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4>
	media: Ethernet autoselect (100baseTX <full-duplex>)

greetings,
cryx