perf kwork: Implement BPF trace

'perf record' generates perf.data, which generates extra interrupts
for hard disk, amount of data to be collected increases with time.

Using eBPF trace can process the data in kernel, which solves the
preceding two problems.

Add -b/--use-bpf option for latency and report to support
tracing kwork events using eBPF:

1. Create bpf prog and attach to tracepoints,
2. Start tracing after command is entered,
3. After user hit "ctrl+c", stop tracing and report,
4. Support CPU and name filtering.

This commit implements the framework code and
does not add specific event support.

Test cases:

  # perf kwork rep -h

   Usage: perf kwork report [<options>]

      -b, --use-bpf         Use BPF to measure kwork runtime
      -C, --cpu <cpu>       list of cpus to profile
      -i, --input <file>    input file name
      -n, --name <name>     event name to profile
      -s, --sort <key[,key2...]>
                            sort by key(s): runtime, max, count
      -S, --with-summary    Show summary with statistics
          --time <str>      Time span for analysis (start,stop)

  # perf kwork lat -h

   Usage: perf kwork latency [<options>]

      -b, --use-bpf         Use BPF to measure kwork latency
      -C, --cpu <cpu>       list of cpus to profile
      -i, --input <file>    input file name
      -n, --name <name>     event name to profile
      -s, --sort <key[,key2...]>
                            sort by key(s): avg, max, count
          --time <str>      Time span for analysis (start,stop)

  # perf kwork lat -b
  Unsupported bpf trace class irq

  # perf kwork rep -b
  Unsupported bpf trace class irq

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220709015033.38326-15-yangjihong1@huawei.com
[ Simplify work_findnew() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/tools/perf/util/kwork.h b/tools/perf/util/kwork.h
index 6a06194304b8..320c0a6d2e08 100644
--- a/tools/perf/util/kwork.h
+++ b/tools/perf/util/kwork.h
@@ -203,6 +203,7 @@ struct perf_kwork {
 	const char *sort_order;
 	bool show_callchain;
 	unsigned int max_stack;
+	bool use_bpf;
 
 	/*
 	 * statistics
@@ -219,4 +220,38 @@ struct perf_kwork {
 	u64 nr_skipped_events[KWORK_TRACE_MAX + 1];
 };
 
+struct kwork_work *perf_kwork_add_work(struct perf_kwork *kwork,
+				       struct kwork_class *class,
+				       struct kwork_work *key);
+
+#ifdef HAVE_BPF_SKEL
+
+int perf_kwork__trace_prepare_bpf(struct perf_kwork *kwork);
+int perf_kwork__report_read_bpf(struct perf_kwork *kwork);
+void perf_kwork__report_cleanup_bpf(void);
+
+void perf_kwork__trace_start(void);
+void perf_kwork__trace_finish(void);
+
+#else  /* !HAVE_BPF_SKEL */
+
+static inline int
+perf_kwork__trace_prepare_bpf(struct perf_kwork *kwork __maybe_unused)
+{
+	return -1;
+}
+
+static inline int
+perf_kwork__report_read_bpf(struct perf_kwork *kwork __maybe_unused)
+{
+	return -1;
+}
+
+static inline void perf_kwork__report_cleanup_bpf(void) {}
+
+static inline void perf_kwork__trace_start(void) {}
+static inline void perf_kwork__trace_finish(void) {}
+
+#endif  /* HAVE_BPF_SKEL */
+
 #endif  /* PERF_UTIL_KWORK_H */