Re: [PATCH 4/4] perf stat: Enable BPF counter with --for-each-cgroup

From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Andi Kleen <ak@linux.intel.com>, Ian Rogers <irogers@google.com>,
	Stephane Eranian <eranian@google.com>,
	Song Liu <songliubraving@fb.com>
Subject: Re: [PATCH 4/4] perf stat: Enable BPF counter with --for-each-cgroup
Date: Thu, 1 Jul 2021 10:10:57 -0700	[thread overview]
Message-ID: <CAM9d7ci833BC_9moyF7pbRLJ=tYxR8GH_y41pS1jcF3vC163bA@mail.gmail.com> (raw)
In-Reply-To: <YN3GgMUFtMCYpNI7@kernel.org>

On Thu, Jul 1, 2021 at 6:43 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> Em Wed, Jun 30, 2021 at 03:50:12PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Fri, Jun 25, 2021 at 12:18:26AM -0700, Namhyung Kim escreveu:
> > > Recently bperf was added to use BPF to count perf events for various
> > > purposes.  This is an extension for the approach and targetting to
> > > cgroup usages.
> > >
> > > Unlike the other bperf, it doesn't share the events with other
> > > processes but it'd reduce unnecessary events (and the overhead of
> > > multiplexing) for each monitored cgroup within the perf session.
> > >
> > > When --for-each-cgroup is used with --bpf-counters, it will open
> > > cgroup-switches event per cpu internally and attach the new BPF
> > > program to read given perf_events and to aggregate the results for
> > > cgroups.  It's only called when task is switched to a task in a
> > > different cgroup.
> >
> > I'll take a stab at fixing these:
>
> So, tried some 'make -C tools clean', etc but I'm now stuck with:
>
>   CLANG   /tmp/build/perf/util/bpf_skel/.tmp/bperf_cgroup.bpf.o
> util/bpf_skel/bperf_cgroup.bpf.c:4:10: fatal error: 'vmlinux.h' file not found
> #include "vmlinux.h"
>          ^~~~~~~~~~~
> 1 error generated.
> make[2]: *** [Makefile.perf:1033: /tmp/build/perf/util/bpf_skel/.tmp/bperf_cgroup.bpf.o] Error 1
> make[2]: *** Waiting for unfinished jobs....
>   CC      /tmp/build/perf/pmu-events/pmu-events.o
>   LD      /tmp/build/perf/pmu-events/pmu-events-in.o
>
> Auto-detecting system features:
> ...                        libbfd: [ on  ]
> ...        disassembler-four-args: [ on  ]
> ...                          zlib: [ on  ]
> ...                        libcap: [ on  ]
> ...               clang-bpf-co-re: [ on  ]
>
>
>   MKDIR   /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/
>   MKDIR   /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/
>
>
> Have to go errands now, will put what I have at tmp.perf/core now.
> Please see if you can reproduce, I use this to build:
>
>     make -k CORESIGHT=1 BUILD_BPF_SKEL=1 PYTHON=python3 DEBUG=1 O=/tmp/build/perf -C tools/perf install-bin
>
> - Arnaldo

Oh, sorry about that.  I found the header generation is misplaced
in the Makefile.perf.  Will fix it in the next version.

Thanks,
Namhyung