Re: missing sytemtap kernel.trace("net*") on newer Fedora kernels

[Josh Stone <jistone at redhat dot com>]

On 06/11/2014 02:33 PM, William Cohen wrote:
> I was looking at the perf netdev-times script:
> 
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/tools/perf/scripts/python/bin/netdev-times-record
> 
> Which uses the following perf tracepoints:
> 
> #!/bin/bash
> perf record -e net:net_dev_xmit -e net:net_dev_queue		\
> 		-e net:netif_receive_skb -e net:netif_rx		\
> 		-e skb:consume_skb -e skb:kfree_skb			\
> 		-e skb:skb_copy_datagram_iovec -e napi:napi_poll	\
> 		-e irq:irq_handler_entry -e irq:irq_handler_exit	\
> 		-e irq:softirq_entry -e irq:softirq_exit		\
> 		-e irq:softirq_raise $@
> 
> 
> On the rhel7 kernel all of the tracepoints are available,  However,
> on Fedora 20 none of the kernel.trace("net*"), kernel.trace("*skb*"),
> or kernel.trace("napi_poll") tracepoints are there.
> 
> Has anyone else noticed the missing tracepoints on Fedora 20?

I see all of these on kernel-3.14.5-200.fc20.x86_64.

You can see all the gory tracepoint-detecting details from your listing
with "stap -vvvv --poison-cache ...".  For instance, napi_poll should
come from include/trace/events/napi.h.  On my system it finds that
header under both /lib/modules and /usr/src/debug, but I even tried
moving the debug tree aside, and it still found the tracepoint.