Re: [PATCH net-next] perf, bpf: minimize the size of perf_trace_() tracepoint handler

[Peter Zijlstra]

On Mon, Apr 18, 2016 at 08:11:50PM -0700, Alexei Starovoitov wrote:
> move trace_call_bpf() into helper function to minimize the size
> of perf_trace_*() tracepoint handlers.
>     text	   data	    bss	    dec	 	   hex	filename
> 10541679	5526646	2945024	19013349	1221ee5	vmlinux_before
> 10509422	5526646	2945024	18981092	121a0e4	vmlinux_after
> 
> It may seem that perf_fetch_caller_regs() can also be moved,
> but that is incorrect, since ip/sp will be wrong.
> 
> bpf+tracepoint performance is not affected, since
> perf_swevent_put_recursion_context() is now inlined.
> export_symbol_gpl can also be dropped.
> 
> No measurable change in normal perf tracepoints.
> 
> Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> ---
>  include/linux/trace_events.h |  5 +++++
>  include/trace/perf.h         | 13 +++----------
>  kernel/events/core.c         | 20 +++++++++++++++++++-
>  3 files changed, 27 insertions(+), 11 deletions(-)
> 

Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

David, please take through the net tree as this depends on prior patches
by Alexei that are already in your tree.