Merge pull request #1192 from palmtenor/perf_config

Unify Perf Event related Enums and checks

src/cc/libbpf.c

@@ -604,10 +604,32 @@ error:
   return NULL;
 }
 
+int invalid_perf_config(uint32_t type, uint64_t config) {
+  switch (type) {
+    case PERF_TYPE_HARDWARE:
+      return config >= PERF_COUNT_HW_MAX;
+    case PERF_TYPE_SOFTWARE:
+      return config >= PERF_COUNT_SW_MAX;
+    case PERF_TYPE_RAW:
+      return 0;
+    default:
+      return 1;
+  }
+}
+
 int bpf_open_perf_event(uint32_t type, uint64_t config, int pid, int cpu) {
   int fd;
   struct perf_event_attr attr = {};
 
+  if (type != PERF_TYPE_HARDWARE && type != PERF_TYPE_RAW) {
+    fprintf(stderr, "Unsupported perf event type\n");
+    return -1;
+  }
+  if (invalid_perf_config(type, config)) {
+    fprintf(stderr, "Invalid perf event config\n");
+    return -1;
+  }
+
   attr.sample_period = LONG_MAX;
   attr.type = type;
   attr.config = config;
@@ -733,8 +755,7 @@ int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config,
     fprintf(stderr, "Unsupported perf event type\n");
     return -1;
   }
-  if ((ev_type == PERF_TYPE_HARDWARE && ev_config >= PERF_COUNT_HW_MAX) ||
-      (ev_type == PERF_TYPE_SOFTWARE && ev_config >= PERF_COUNT_SW_MAX)) {
+  if (invalid_perf_config(ev_type, ev_config)) {
     fprintf(stderr, "Invalid perf event config\n");
     return -1;
   }

src/python/bcc/table.py

@@ -468,41 +468,6 @@ class ProgArray(ArrayBase):
             raise Exception("Could not delete item")
 
 class PerfEventArray(ArrayBase):
-    class Event(object):
-        def __init__(self, typ, config):
-            self.typ = typ
-            self.config = config
-
-    HW_CPU_CYCLES                = Event(Perf.PERF_TYPE_HARDWARE, 0)
-    HW_INSTRUCTIONS              = Event(Perf.PERF_TYPE_HARDWARE, 1)
-    HW_CACHE_REFERENCES          = Event(Perf.PERF_TYPE_HARDWARE, 2)
-    HW_CACHE_MISSES              = Event(Perf.PERF_TYPE_HARDWARE, 3)
-    HW_BRANCH_INSTRUCTIONS       = Event(Perf.PERF_TYPE_HARDWARE, 4)
-    HW_BRANCH_MISSES             = Event(Perf.PERF_TYPE_HARDWARE, 5)
-    HW_BUS_CYCLES                = Event(Perf.PERF_TYPE_HARDWARE, 6)
-    HW_STALLED_CYCLES_FRONTEND   = Event(Perf.PERF_TYPE_HARDWARE, 7)
-    HW_STALLED_CYCLES_BACKEND    = Event(Perf.PERF_TYPE_HARDWARE, 8)
-    HW_REF_CPU_CYCLES            = Event(Perf.PERF_TYPE_HARDWARE, 9)
-
-    # not yet supported, wip
-    #HW_CACHE_L1D_READ        = Event(Perf.PERF_TYPE_HW_CACHE, 0<<0|0<<8|0<<16)
-    #HW_CACHE_L1D_READ_MISS   = Event(Perf.PERF_TYPE_HW_CACHE, 0<<0|0<<8|1<<16)
-    #HW_CACHE_L1D_WRITE       = Event(Perf.PERF_TYPE_HW_CACHE, 0<<0|1<<8|0<<16)
-    #HW_CACHE_L1D_WRITE_MISS  = Event(Perf.PERF_TYPE_HW_CACHE, 0<<0|1<<8|1<<16)
-    #HW_CACHE_L1D_PREF        = Event(Perf.PERF_TYPE_HW_CACHE, 0<<0|2<<8|0<<16)
-    #HW_CACHE_L1D_PREF_MISS   = Event(Perf.PERF_TYPE_HW_CACHE, 0<<0|2<<8|1<<16)
-    #HW_CACHE_L1I_READ        = Event(Perf.PERF_TYPE_HW_CACHE, 1<<0|0<<8|0<<16)
-    #HW_CACHE_L1I_READ_MISS   = Event(Perf.PERF_TYPE_HW_CACHE, 1<<0|0<<8|1<<16)
-    #HW_CACHE_L1I_WRITE       = Event(Perf.PERF_TYPE_HW_CACHE, 1<<0|1<<8|0<<16)
-    #HW_CACHE_L1I_WRITE_MISS  = Event(Perf.PERF_TYPE_HW_CACHE, 1<<0|1<<8|1<<16)
-    #HW_CACHE_L1I_PREF        = Event(Perf.PERF_TYPE_HW_CACHE, 1<<0|2<<8|0<<16)
-    #HW_CACHE_L1I_PREF_MISS   = Event(Perf.PERF_TYPE_HW_CACHE, 1<<0|2<<8|1<<16)
-    #HW_CACHE_LL_READ         = Event(Perf.PERF_TYPE_HW_CACHE, 2<<0|0<<8|0<<16)
-    #HW_CACHE_LL_READ_MISS    = Event(Perf.PERF_TYPE_HW_CACHE, 2<<0|0<<8|1<<16)
-    #HW_CACHE_LL_WRITE        = Event(Perf.PERF_TYPE_HW_CACHE, 2<<0|1<<8|0<<16)
-    #HW_CACHE_LL_WRITE_MISS   = Event(Perf.PERF_TYPE_HW_CACHE, 2<<0|1<<8|1<<16)
-    #HW_CACHE_LL_PREF         = Event(Perf.PERF_TYPE_HW_CACHE, 2<<0|2<<8|0<<16)
-    #HW_CACHE_LL_PREF_MISS    = Event(Perf.PERF_TYPE_HW_CACHE, 2<<0|2<<8|1<<16)
 
     def __init__(self, *args, **kwargs):
         super(PerfEventArray, self).__init__(*args, **kwargs)
@@ -556,18 +521,15 @@ class PerfEventArray(ArrayBase):
             # the fd is kept open in the map itself by the kernel
             os.close(fd)
 
-    def open_perf_event(self, ev):
-        """open_perf_event(ev)
+    def open_perf_event(self, typ, config):
+        """open_perf_event(typ, config)
 
         Configures the table such that calls from the bpf program to
         table.perf_read(bpf_get_smp_processor_id()) will return the hardware
         counter denoted by event ev on the local cpu.
         """
-        if not isinstance(ev, self.Event):
-            raise Exception("argument must be an Event, got %s", type(ev))
-
         for i in get_online_cpus():
-            self._open_perf_event(i, ev.typ, ev.config)
+            self._open_perf_event(i, typ, config)
 
 
 class PerCpuHash(HashTable):

tests/python/test_perf_event.py

@@ -18,12 +18,20 @@ BPF_HISTOGRAM(dist);
 int kprobe__sys_getuid(void *ctx) {
     u32 cpu = bpf_get_smp_processor_id();
     u64 val = cnt1.perf_read(cpu);
+
+    if (((s64)val < 0) && ((s64)val > -256))
+        return 0;
+
     prev.update(&cpu, &val);
     return 0;
 }
 int kretprobe__sys_getuid(void *ctx) {
     u32 cpu = bpf_get_smp_processor_id();
     u64 val = cnt1.perf_read(cpu);
+
+    if (((s64)val < 0) && ((s64)val > -256))
+        return 0;
+
     u64 *prevp = prev.lookup(&cpu);
     if (prevp)
         dist.increment(bpf_log2l(val - *prevp));
@@ -34,7 +42,7 @@ int kretprobe__sys_getuid(void *ctx) {
                 cflags=["-DNUM_CPUS=%d" % multiprocessing.cpu_count()])
         cnt1 = b["cnt1"]
         try:
-            cnt1.open_perf_event(cnt1.HW_CPU_CYCLES)
+            cnt1.open_perf_event(bcc.PerfType.HARDWARE, bcc.PerfHWConfig.CPU_CYCLES)
         except:
             if ctypes.get_errno() == 2:
                 raise self.skipTest("hardware events unsupported")