Fix perf event API implementations

- Set `inherit = 1` only for per-task perf event. Inspired from change
  torvalds/linux@81b9cf8
- Kernel now support more events (see #1448). Also it's checked in
  `bpf_attach_perf_event` already. Remove the check from C++ API

src/cc/api/BPF.cc

@@ -15,7 +15,6 @@
  */
 
 #include <linux/bpf.h>
-#include <linux/perf_event.h>
 #include <unistd.h>
 #include <cstdio>
 #include <cstring>
@@ -417,8 +416,6 @@ StatusTuple BPF::open_perf_event(const std::string& name,
  name.c_str());
  perf_event_arrays_[name] = new BPFPerfEventArray(it->second);
  }
- if (type != PERF_TYPE_RAW && type != PERF_TYPE_HARDWARE)
- return StatusTuple(-1, "open_perf_event unsupported type");
  auto table = perf_event_arrays_[name];
  TRY2(table->open_all_cpu(type, config));
  return StatusTuple(0);

src/cc/api/BPFTable.cc

@@ -107,7 +107,7 @@ BPFStackTable::~BPFStackTable() {
 }
 
 void BPFStackTable::clear_table_non_atomic() {
- for (int i = 0; i < capacity(); i++) {
+ for (int i = 0; size_t(i) < capacity(); i++) {
  remove(&i);
  }
 }

src/cc/libbpf.c

@@ -1054,7 +1054,8 @@ int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config,
  struct perf_event_attr attr = {};
  attr.type = ev_type;
  attr.config = ev_config;
- attr.inherit = 1;
+ if (pid > 0)
+ attr.inherit = 1;
  if (sample_freq > 0) {
  attr.freq = 1;
  attr.sample_freq = sample_freq;