Re: BPF runtime for systemtap

[fche@redhat.com (Frank Ch. Eigler)]

brendan.d.gregg wrote:

> [...]
> Great! Is there a hello world example in there somewhere? I found this:
> [...]

Yup.  Here is a smoke test.  (A great many other things are not yet
working.)

% sudo ./stap  -v  --runtime=bpf -e 'global foo
    probe kprobe.function("vfs_read"), kprobe.function("do_select") { foo++ } 
    probe begin { printf("systemtap starting probe\n") }
    probe end { printf("systemtap ending probe\n"); printf("foo = %d\n", foo) }'

Pass 1: parsed user script and 35 library scripts using 198460virt/15804res/6416shr/9208data kb, in 0usr/0sys/71real ms.
Pass 2: analyzed script: 4 probes, 0 functions, 0 embeds, 1 global using 198460virt/15804res/6416shr/9208data kb, in 0usr/0sys/0real ms.
Pass 4: compiled BPF into "stap_32349.bo" in 0usr/0sys/0real ms.
Pass 5: starting run.
systemtap starting probe
^Csystemtap ending probe
foo = 108812
Pass 5: run completed in 0usr/10sys/2525real ms.