Re: [PATCH v4 bpf-next 0/4] bpftool: introduce prog profile

From: Song Liu <songliubraving@fb.com>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
	"quentin@isovalent.com" <quentin@isovalent.com>,
	Kernel Team <Kernel-team@fb.com>,
	"ast@kernel.org" <ast@kernel.org>,
	"daniel@iogearbox.net" <daniel@iogearbox.net>,
	"arnaldo.melo@gmail.com" <arnaldo.melo@gmail.com>,
	"jolsa@kernel.org" <jolsa@kernel.org>
Subject: Re: [PATCH v4 bpf-next 0/4] bpftool: introduce prog profile
Date: Wed, 4 Mar 2020 21:16:29 +0000	[thread overview]
Message-ID: <C7C4E8E1-9176-48DC-8089-D4AEDE86E720@fb.com> (raw)
In-Reply-To: <20200304204158.GD168640@krava>


> On Mar 4, 2020, at 12:41 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Mar 04, 2020 at 08:08:07PM +0100, Jiri Olsa wrote:
>> On Wed, Mar 04, 2020 at 10:07:06AM -0800, Song Liu wrote:
>>> This set introduces bpftool prog profile command, which uses hardware
>>> counters to profile BPF programs.
>>> 
>>> This command attaches fentry/fexit programs to a target program. These two
>>> programs read hardware counters before and after the target program and
>>> calculate the difference.
>>> 
>>> Changes v3 => v4:
>>> 1. Simplify err handling in profile_open_perf_events() (Quentin);
>>> 2. Remove redundant p_err() (Quentin);
>>> 3. Replace tab with space in bash-completion; (Quentin);
>>> 4. Fix typo _bpftool_get_map_names => _bpftool_get_prog_names (Quentin).
>> 
>> hum, I'm getting:
>> 
>> 	[jolsa@dell-r440-01 bpftool]$ pwd
>> 	/home/jolsa/linux-perf/tools/bpf/bpftool
>> 	[jolsa@dell-r440-01 bpftool]$ make
>> 	...
>> 	make[1]: Leaving directory '/home/jolsa/linux-perf/tools/lib/bpf'
>> 	  LINK     _bpftool
>> 	make: *** No rule to make target 'skeleton/profiler.bpf.c', needed by 'skeleton/profiler.bpf.o'.  Stop.
> 
> ok, I had to apply your patches by hand, because 'git am' refused to
> due to fuzz.. so some of you new files did not make it to my tree ;-)
> 
> anyway I hit another error now:
> 
> 	  CC       prog.o
> 	In file included from prog.c:1553:
> 	profiler.skel.h: In function ‘profiler_bpf__create_skeleton’:
> 	profiler.skel.h:136:35: error: ‘struct profiler_bpf’ has no member named ‘rodata’
> 	  136 |  s->maps[4].mmaped = (void **)&obj->rodata;
> 	      |                                   ^~
> 	prog.c: In function ‘profile_read_values’:
> 	prog.c:1650:29: error: ‘struct profiler_bpf’ has no member named ‘rodata’
> 	 1650 |  __u32 m, cpu, num_cpu = obj->rodata->num_cpu;
> 
> I'll try to figure it out.. might be error on my end
> 
> do you have git repo with these changes?

I pushed it to 

https://git.kernel.org/pub/scm/linux/kernel/git/song/linux.git/tree/?h=bpf-per-prog-stats

Thanks,
Song