Re: When does Linux drop UDP packets?

From: Steven Rostedt
Date: Thu Jun 04 2009 - 17:08:01 EST



On Thu, 4 Jun 2009, Jaswinder Singh Rajput wrote:

> On Thu, 2009-06-04 at 12:34 -0400, Steven Rostedt wrote:
>
> > BTW, I used ftrace to look into this:
> >
> > Enable:
> >
> > CONFIG_FTRACE
> > CONFIG_FUNCTION_TRACER
> > CONFIG_FUNCITON_GRAPH_TRACER
> > CONFIG_DYNAMIC_FTRACE
> >
> > Compile and boot:
> >
> > # mount -t debugfs nodev /sys/kernel/debug
>
> Very glad to see you following standards ;-)

I only did that to not hear the debugfs nazis squack.

>
> > # cd /sys/kernel/debug
>
> hmm you mean # cd /sys/kernel/debug/tracing

A mistake I would not have made if I just did /debug

>
> > # echo udp_rcv > set_graph_function
> > # echo function_graph > current_tracer
> > # cat trace
> >
>
> Anyway you can also see UDP packet drops when you increase network and
> CPU load.

That's not the issue here.

-- Steve

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