GE traffic statistics (/proc/net/dev)

Date: Thu Jun 05 2003 - 09:20:05 EST

Hi all

I have a GE NIC card working in receive only mode capturing all traffic at
80Gbps in a 2-way SMP Pentium-III system.

I found very extrange that, for this device, stats on /proc/net/dev updates
each second (more or less), that is, not in sub-second intervals. Again note
this only happens for this device and not for other NIC card (Fast-Ethernet
card, e100).

I'm quite sure that the nic is receiving the traffic smootly,
because interrupts are distributed smoothly in the time in /proc/interrupts
(I talk about sub second intervals here). Tthe GE card makes around 10000

Also I think packets are forwarded to the CPU smoothly (not in chunks each second)
because measurements of timestamps and RTT calculations I made.

I'm curious why just this device updates stats this way.

I'm running vanilla 2.4.20

Any comment will be greatly appreciated

Thanks in advance


some aditional info about the GE nic

00:0b.0 Ethernet controller: BROADCOM Corporation NetXtreme BCM5701 Gigabit
Ethernet (rev 15)
        Subsystem: 3Com Corporation 3C996B-T 1000BaseTX
        Flags: bus master, 66Mhz, medium devsel, latency 64, IRQ 18
        Memory at f4000000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: <available only to root>

this card is working in a 32bit bus at 33Mhz

eth1: Tigon3 [partno(3C996B-T) rev 0105 PHY(5701)] (PCI:33MHz:32-bit) 10/100/1000BaseT Ethernet 00:04:76:f6:8a:a0
tg3: eth1: Link is up at 1000 Mbps, full duplex.
tg3: eth1: Flow control is off for TX and off for RX.

                Debian GNU/Linux: a dream come true
"Computers are useless. They can only give answers." Pablo Picasso

---> Visita para saber acerca de la <---
---> Asociación Valenciana de Usuarios de Linux <---
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Sat Jun 07 2003 - 22:00:27 EST