X86_64 perf counter plugin

Change-Id: Ie5a00c15ee9536cc61afab57f6cadc1aa1972f3c
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 433 insertions, 0 deletions

diff --git a/src/plugins/perfmon/perfmon_periodic.c b/src/plugins/perfmon/perfmon_periodic.c
new file mode 100644
index 00000000000..329a75d7305
--- /dev/null
+++ b/src/plugins/perfmon/perfmon_periodic.c
@@ -0,0 +1,433 @@
+/*
+ * perfmon_periodic.c - skeleton plug-in periodic function
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vppinfra/error.h>
+#include <perfmon/perfmon.h>
+#include <asm/unistd.h>
+#include <sys/ioctl.h>
+
+static long
+perf_event_open (struct perf_event_attr *hw_event, pid_t pid, int cpu,
+		 int group_fd, unsigned long flags)
+{
+  int ret;
+
+  ret = syscall (__NR_perf_event_open, hw_event, pid, cpu, group_fd, flags);
+  return ret;
+}
+
+static u64
+read_current_perf_counter (vlib_main_t * vm)
+{
+  if (vm->perf_counter_id)
+    return clib_rdpmc (vm->perf_counter_id);
+  else
+    {
+      u64 sw_value;
+      if (read (vm->perf_counter_fd, &sw_value, sizeof (sw_value)) !=
+	  sizeof (sw_value))
+	{
+	  clib_unix_warning ("counter read failed, disable collection...");
+	  vm->vlib_node_runtime_perf_counter_cb = 0;
+	  return 0ULL;
+	}
+      return sw_value;
+    }
+}
+
+static void
+clear_counters (perfmon_main_t * pm)
+{
+  int i, j;
+  vlib_main_t *vm = pm->vlib_main;
+  vlib_main_t *stat_vm;
+  vlib_node_main_t *nm;
+  vlib_node_t *n;
+
+  vlib_worker_thread_barrier_sync (vm);
+
+  for (j = 0; j < vec_len (vlib_mains); j++)
+    {
+      stat_vm = vlib_mains[j];
+      if (stat_vm == 0)
+	continue;
+
+      nm = &stat_vm->node_main;
+
+      /* Clear the node runtime perfmon counters */
+      for (i = 0; i < vec_len (nm->nodes); i++)
+	{
+	  n = nm->nodes[i];
+	  vlib_node_sync_stats (stat_vm, n);
+	}
+
+      /* And clear the node perfmon counters */
+      for (i = 0; i < vec_len (nm->nodes); i++)
+	{
+	  n = nm->nodes[i];
+	  n->stats_total.perf_counter_ticks = 0;
+	  n->stats_total.perf_counter_vectors = 0;
+	  n->stats_last_clear.perf_counter_ticks = 0;
+	  n->stats_last_clear.perf_counter_vectors = 0;
+	}
+    }
+  vlib_worker_thread_barrier_release (vm);
+}
+
+static void
+enable_current_event (perfmon_main_t * pm)
+{
+  struct perf_event_attr pe;
+  int fd;
+  struct perf_event_mmap_page *p = 0;
+  perfmon_event_config_t *c;
+  vlib_main_t *vm = vlib_get_main ();
+  u32 my_thread_index = vm->thread_index;
+
+  c = vec_elt_at_index (pm->events_to_collect, pm->current_event);
+
+  memset (&pe, 0, sizeof (struct perf_event_attr));
+  pe.type = c->pe_type;
+  pe.size = sizeof (struct perf_event_attr);
+  pe.config = c->pe_config;
+  pe.disabled = 1;
+  pe.pinned = 1;
+  /*
+   * Note: excluding the kernel makes the
+   * (software) context-switch counter read 0...
+   */
+  if (pe.type != PERF_TYPE_SOFTWARE)
+    {
+      /* Exclude kernel and hypervisor */
+      pe.exclude_kernel = 1;
+      pe.exclude_hv = 1;
+    }
+
+  fd = perf_event_open (&pe, 0, -1, -1, 0);
+  if (fd == -1)
+    {
+      clib_unix_warning ("event open: type %d config %d", c->pe_type,
+			 c->pe_config);
+      return;
+    }
+
+  if (pe.type != PERF_TYPE_SOFTWARE)
+    {
+      p = mmap (0, pm->page_size, PROT_READ, MAP_SHARED, fd, 0);
+      if (p == MAP_FAILED)
+	{
+	  clib_unix_warning ("mmap");
+	  close (fd);
+	  return;
+	}
+    }
+
+  if (ioctl (fd, PERF_EVENT_IOC_RESET, 0) < 0)
+    clib_unix_warning ("reset ioctl");
+
+  if (ioctl (fd, PERF_EVENT_IOC_ENABLE, 0) < 0)
+    clib_unix_warning ("enable ioctl");
+
+  /*
+   * Software event counters - and others not capable of being
+   * read via the "rdpmc" instruction - will be read
+   * by system calls.
+   */
+  if (pe.type == PERF_TYPE_SOFTWARE || p->cap_user_rdpmc == 0)
+    pm->rdpmc_indices[my_thread_index] = 0;
+  else				/* use rdpmc instrs */
+    pm->rdpmc_indices[my_thread_index] = p->index - 1;
+  pm->perf_event_pages[my_thread_index] = (void *) p;
+
+  pm->pm_fds[my_thread_index] = fd;
+
+  /* Enable the main loop counter snapshot mechanism */
+  vm->perf_counter_id = pm->rdpmc_indices[my_thread_index];
+  vm->perf_counter_fd = fd;
+  vm->vlib_node_runtime_perf_counter_cb = read_current_perf_counter;
+}
+
+static void
+disable_event (perfmon_main_t * pm)
+{
+  vlib_main_t *vm = vlib_get_main ();
+  u32 my_thread_index = vm->thread_index;
+
+  if (pm->pm_fds[my_thread_index] == 0)
+    return;
+
+  /* Stop main loop collection */
+  vm->vlib_node_runtime_perf_counter_cb = 0;
+
+  if (ioctl (pm->pm_fds[my_thread_index], PERF_EVENT_IOC_DISABLE, 0) < 0)
+    clib_unix_warning ("disable ioctl");
+
+  if (pm->perf_event_pages[my_thread_index])
+    if (munmap (pm->perf_event_pages[my_thread_index], pm->page_size) < 0)
+      clib_unix_warning ("munmap");
+
+  (void) close (pm->pm_fds[my_thread_index]);
+  pm->pm_fds[my_thread_index] = 0;
+}
+
+static void
+worker_thread_start_event (vlib_main_t * vm)
+{
+  perfmon_main_t *pm = &perfmon_main;
+
+  enable_current_event (pm);
+  vm->worker_thread_main_loop_callback = 0;
+}
+
+static void
+worker_thread_stop_event (vlib_main_t * vm)
+{
+  perfmon_main_t *pm = &perfmon_main;
+  disable_event (pm);
+  vm->worker_thread_main_loop_callback = 0;
+}
+
+static void
+start_event (perfmon_main_t * pm, f64 now, uword event_data)
+{
+  int i;
+  pm->current_event = 0;
+  if (vec_len (pm->events_to_collect) == 0)
+    {
+      pm->state = PERFMON_STATE_OFF;
+      return;
+    }
+  pm->state = PERFMON_STATE_RUNNING;
+  clear_counters (pm);
+
+  /* Start collection on this thread */
+  enable_current_event (pm);
+
+  /* And also on worker threads */
+  for (i = 1; i < vec_len (vlib_mains); i++)
+    {
+      if (vlib_mains[i] == 0)
+	continue;
+      vlib_mains[i]->worker_thread_main_loop_callback = (void *)
+	worker_thread_start_event;
+    }
+}
+
+void
+scrape_and_clear_counters (perfmon_main_t * pm)
+{
+  int i, j;
+  vlib_main_t *vm = pm->vlib_main;
+  vlib_main_t *stat_vm;
+  vlib_node_main_t *nm;
+  vlib_node_t ***node_dups = 0;
+  vlib_node_t **nodes;
+  vlib_node_t *n;
+  perfmon_capture_t *c;
+  perfmon_event_config_t *current_event;
+  uword *p;
+  u8 *counter_name;
+  u64 counter_value;
+  u64 vectors_this_counter;
+
+  /* snapshoot the nodes, including pm counters */
+  vlib_worker_thread_barrier_sync (vm);
+
+  for (j = 0; j < vec_len (vlib_mains); j++)
+    {
+      stat_vm = vlib_mains[j];
+      if (stat_vm == 0)
+	continue;
+
+      nm = &stat_vm->node_main;
+
+      for (i = 0; i < vec_len (nm->nodes); i++)
+	{
+	  n = nm->nodes[i];
+	  vlib_node_sync_stats (stat_vm, n);
+	}
+
+      nodes = 0;
+      vec_validate (nodes, vec_len (nm->nodes) - 1);
+      vec_add1 (node_dups, nodes);
+
+      /* Snapshoot and clear the per-node perfmon counters */
+      for (i = 0; i < vec_len (nm->nodes); i++)
+	{
+	  n = nm->nodes[i];
+	  nodes[i] = clib_mem_alloc (sizeof (*n));
+	  clib_memcpy (nodes[i], n, sizeof (*n));
+	  n->stats_total.perf_counter_ticks = 0;
+	  n->stats_total.perf_counter_vectors = 0;
+	  n->stats_last_clear.perf_counter_ticks = 0;
+	  n->stats_last_clear.perf_counter_vectors = 0;
+	}
+    }
+
+  vlib_worker_thread_barrier_release (vm);
+
+  current_event = pm->events_to_collect + pm->current_event;
+
+  for (j = 0; j < vec_len (vlib_mains); j++)
+    {
+      stat_vm = vlib_mains[j];
+      if (stat_vm == 0)
+	continue;
+
+      nodes = node_dups[j];
+
+      for (i = 0; i < vec_len (nodes); i++)
+	{
+	  u8 *capture_name;
+
+	  n = nodes[i];
+	  if (n->stats_total.perf_counter_ticks == 0)
+	    {
+	      clib_mem_free (n);
+	      continue;
+	    }
+
+	  capture_name = format (0, "t%d-%v%c", j, n->name, 0);
+
+	  p = hash_get_mem (pm->capture_by_thread_and_node_name,
+			    capture_name);
+
+	  if (p == 0)
+	    {
+	      pool_get (pm->capture_pool, c);
+	      memset (c, 0, sizeof (*c));
+	      c->thread_and_node_name = capture_name;
+	      hash_set_mem (pm->capture_by_thread_and_node_name,
+			    capture_name, c - pm->capture_pool);
+	    }
+	  else
+	    c = pool_elt_at_index (pm->capture_pool, p[0]);
+
+	  /* Snapshoot counters, etc. into the capture */
+	  counter_name = (u8 *) current_event->name;
+	  counter_value = n->stats_total.perf_counter_ticks -
+	    n->stats_last_clear.perf_counter_ticks;
+	  vectors_this_counter = n->stats_total.perf_counter_vectors -
+	    n->stats_last_clear.perf_counter_vectors;
+
+	  vec_add1 (c->counter_names, counter_name);
+	  vec_add1 (c->counter_values, counter_value);
+	  vec_add1 (c->vectors_this_counter, vectors_this_counter);
+	  clib_mem_free (n);
+	}
+      vec_free (nodes);
+    }
+  vec_free (node_dups);
+}
+
+static void
+handle_timeout (perfmon_main_t * pm, f64 now)
+{
+  int i;
+  disable_event (pm);
+
+  /* And also on worker threads */
+  for (i = 1; i < vec_len (vlib_mains); i++)
+    {
+      if (vlib_mains[i] == 0)
+	continue;
+      vlib_mains[i]->worker_thread_main_loop_callback = (void *)
+	worker_thread_stop_event;
+    }
+
+  /* Short delay to make sure workers have stopped collection */
+  if (i > 1)
+    vlib_process_suspend (pm->vlib_main, 1e-3);
+  scrape_and_clear_counters (pm);
+  pm->current_event++;
+  if (pm->current_event >= vec_len (pm->events_to_collect))
+    {
+      pm->current_event = 0;
+      pm->state = PERFMON_STATE_OFF;
+      return;
+    }
+  enable_current_event (pm);
+
+  /* And also on worker threads */
+  for (i = 1; i < vec_len (vlib_mains); i++)
+    {
+      if (vlib_mains[i] == 0)
+	continue;
+      vlib_mains[i]->worker_thread_main_loop_callback = (void *)
+	worker_thread_start_event;
+    }
+}
+
+static uword
+perfmon_periodic_process (vlib_main_t * vm,
+			  vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  perfmon_main_t *pm = &perfmon_main;
+  f64 now;
+  uword *event_data = 0;
+  uword event_type;
+  int i;
+
+  while (1)
+    {
+      if (pm->state == PERFMON_STATE_RUNNING)
+	vlib_process_wait_for_event_or_clock (vm, pm->timeout_interval);
+      else
+	vlib_process_wait_for_event (vm);
+
+      now = vlib_time_now (vm);
+
+      event_type = vlib_process_get_events (vm, (uword **) & event_data);
+
+      switch (event_type)
+	{
+	case PERFMON_START:
+	  for (i = 0; i < vec_len (event_data); i++)
+	    start_event (pm, now, event_data[i]);
+	  break;
+
+	  /* Handle timeout */
+	case ~0:
+	  handle_timeout (pm, now);
+	  break;
+
+	default:
+	  clib_warning ("Unexpected event %d", event_type);
+	  break;
+	}
+      vec_reset_length (event_data);
+    }
+  return 0;			/* or not */
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (perfmon_periodic_node) =
+{
+  .function = perfmon_periodic_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "perfmon-periodic-process",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */