explanation about /proc/net

[Bill Rugolsky Jr.]

On Fri, Sep 28, 2007 at 09:30:27AM -0400, chloe K wrote:
> Hi all
> 
> How can I find out the /proc/net info
> 
> eg: softnet_stat is for what purpose

Much of this is only well-documented in the code.  Here's an attempt
at interpreting softnet_stat [no guarantee that it is correct; read the code!]:

% softnet_stat.sh 
cpu      total    dropped   squeezed  collision
  0 1794619684          0        346          0
  1   36399632          0         74          2

% softnet_stat.sh -h
usage: softnet_stat.sh [ -h ]

Output column definitions:
      cpu  # of the cpu 

    total  # of packets (not including netpoll) received by the interrupt handler
             There might be some double counting going on:
                net/core/dev.c:1643: __get_cpu_var(netdev_rx_stat).total++;
                net/core/dev.c:1836: __get_cpu_var(netdev_rx_stat).total++;
             I think the intention was that these were originally on separate
             receive paths ... 

  dropped  # of packets that were dropped because netdev_max_backlog was exceeded

 squeezed  # of times ksoftirq ran out of netdev_budget or time slice with work
             remaining

collision  # of times that two cpus collided trying to get the device queue lock.

The script is attached.

Regards,

	Bill Rugolsky

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