Subject: Re: [PATCH v2] bpf: BPF based latency tracing

From: Alexei Starovoitov <[email-masked]>
Date: Fri, 19 Jun 2015 17:53:57 -0700

On 6/19/15 7:00 AM, Daniel Wagner wrote:
> BPF offers another way to generate latency histograms. We attach
> kprobes at trace_preempt_off and trace_preempt_on and calculate the
> time it takes to from seeing the off/on transition.
...
> Signed-off-by: Daniel Wagner <[email-masked]>
...
> With the rebase on net-next no additinal patches are needed and this
> thing here runs fine.
...
> samples/bpf/Makefile       |   4 ++
>   samples/bpf/lathist_kern.c |  99 +++++++++++++++++++++++++++++++++++++++++++
>   samples/bpf/lathist_user.c | 103 +++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 206 insertions(+)
>   create mode 100644 samples/bpf/lathist_kern.c
>   create mode 100644 samples/bpf/lathist_user.c

Thanks. That's a useful example.
Acked-by: Alexei Starovoitov <[email-masked]>

Dave,
this patch is for net-next and I hope it's not too late
for this merge window.