perfmon.c

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/*
 * Copyright (c) 2020 Cisco and/or its affiliates.
 * 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 <vnet/vnet.h>
 
#include <vlibapi/api.h>
#include <vlibmemory/api.h>
#include <vnet/plugin/plugin.h>
#include <vpp/app/version.h>
#include <linux/limits.h>
#include <sys/ioctl.h>
 
#include <perfmon/perfmon.h>
 
perfmon_main_t perfmon_main;
 
VLIB_PLUGIN_REGISTER () = {
  .version = VPP_BUILD_VER,
  .description = "Performance Monitor",
};
 
VLIB_REGISTER_LOG_CLASS (if_default_log, static) = {
  .class_name = "perfmon",
};
 
#define log_debug(fmt, ...)                                                   \
  vlib_log_debug (if_default_log.class, fmt, __VA_ARGS__)
#define log_warn(fmt, ...)                                                    \
  vlib_log_warn (if_default_log.class, fmt, __VA_ARGS__)
#define log_err(fmt, ...) vlib_log_err (if_default_log.class, fmt, __VA_ARGS__)
 
void
perfmon_reset (vlib_main_t *vm)
{
  perfmon_main_t *pm = &perfmon_main;
  uword page_size = clib_mem_get_page_size ();
 
  if (pm->is_running)
    for (int i = 0; i < vlib_get_n_threads (); i++)
      vlib_node_set_dispatch_wrapper (vlib_get_main_by_index (i), 0);
 
  for (int i = 0; i < vec_len (pm->fds_to_close); i++)
    close (pm->fds_to_close[i]);
  vec_free (pm->fds_to_close);
  vec_free (pm->group_fds);
  if (pm->default_instance_type)
    {
      perfmon_instance_type_t *it = pm->default_instance_type;
      for (int i = 0; i < vec_len (it->instances); i++)
        vec_free (it->instances[i].name);
      vec_free (it->instances);
      vec_free (pm->default_instance_type);
    }
 
  for (int i = 0; i < vec_len (pm->thread_runtimes); i++)
    {
      perfmon_thread_runtime_t *tr = vec_elt_at_index (pm->thread_runtimes, i);
      vec_free (tr->node_stats);
      for (int j = 0; j < PERF_MAX_EVENTS; j++)
        if (tr->mmap_pages[j])
          munmap (tr->mmap_pages, page_size);
    }
  vec_free (pm->thread_runtimes);
 
  pm->is_running = 0;
  pm->active_instance_type = 0;
  pm->active_bundle = 0;
}
 
static clib_error_t *
perfmon_set (vlib_main_t *vm, perfmon_bundle_t *b)
{
  clib_error_t *err = 0;
  perfmon_main_t *pm = &perfmon_main;
  perfmon_source_t *s;
  int is_node = 0;
  int n_nodes = vec_len (vm->node_main.nodes);
  uword page_size = clib_mem_get_page_size ();
  u32 instance_type = 0;
  perfmon_event_t *e;
  perfmon_instance_type_t *it = 0;
 
  perfmon_reset (vm);
 
  s = b->src;
  ASSERT (b->n_events);
 
  if (b->type == PERFMON_BUNDLE_TYPE_NODE)
    is_node = 1;
 
  if (s->instances_by_type == 0)
    {
      vec_add2 (pm->default_instance_type, it, 1);
      it->name = is_node ? "Thread/Node" : "Thread";
      for (int i = 0; i < vlib_get_n_threads (); i++)
        {
          vlib_worker_thread_t *w = vlib_worker_threads + i;
          perfmon_instance_t *in;
          vec_add2 (it->instances, in, 1);
          in->cpu = w->cpu_id;
          in->pid = w->lwp;
          in->name = (char *) format (0, "%s (%u)%c", w->name, i, 0);
        }
      if (is_node)
        vec_validate (pm->thread_runtimes, vlib_get_n_threads () - 1);
    }
  else
    {
      e = s->events + b->events[0];
 
      if (e->type_from_instance)
        {
          instance_type = e->instance_type;
          for (int i = 1; i < b->n_events; i++)
            {
              e = s->events + b->events[i];
              ASSERT (e->type_from_instance == 1 &&
                      e->instance_type == instance_type);
            }
        }
      it = vec_elt_at_index (s->instances_by_type, instance_type);
    }
 
  pm->active_instance_type = it;
 
  for (int i = 0; i < vec_len (it->instances); i++)
    {
      perfmon_instance_t *in = vec_elt_at_index (it->instances, i);
 
      vec_validate (pm->group_fds, i);
      pm->group_fds[i] = -1;
 
      for (int j = 0; j < b->n_events; j++)
        {
          int fd;
          perfmon_event_t *e = s->events + b->events[j];
          struct perf_event_attr pe = {
            .size = sizeof (struct perf_event_attr),
            .type = e->type_from_instance ? in->type : e->type,
            .config = e->config,
            .exclude_kernel = e->exclude_kernel,
            .read_format =
              (PERF_FORMAT_GROUP | PERF_FORMAT_TOTAL_TIME_ENABLED |
               PERF_FORMAT_TOTAL_TIME_RUNNING),
            .disabled = 1,
          };
 
          log_debug ("perf_event_open pe.type=%u pe.config=0x%x pid=%d "
                     "cpu=%d group_fd=%d",
                     pe.type, pe.config, in->pid, in->cpu, pm->group_fds[i]);
          fd = syscall (__NR_perf_event_open, &pe, in->pid, in->cpu,
                        pm->group_fds[i], 0);
 
          if (fd == -1)
            {
              err = clib_error_return_unix (0, "perf_event_open");
              goto error;
            }
 
          vec_add1 (pm->fds_to_close, fd);
 
          if (pm->group_fds[i] == -1)
            pm->group_fds[i] = fd;
 
          if (is_node)
            {
              perfmon_thread_runtime_t *tr;
              tr = vec_elt_at_index (pm->thread_runtimes, i);
              tr->mmap_pages[j] =
                mmap (0, page_size, PROT_READ, MAP_SHARED, fd, 0);
 
              if (tr->mmap_pages[j] == MAP_FAILED)
                {
                  err = clib_error_return_unix (0, "mmap");
                  goto error;
                }
            }
        }
 
      if (is_node)
        {
          perfmon_thread_runtime_t *rt;
          rt = vec_elt_at_index (pm->thread_runtimes, i);
          rt->bundle = b;
          rt->n_events = b->n_events;
          rt->n_nodes = n_nodes;
          vec_validate_aligned (rt->node_stats, n_nodes - 1,
                                CLIB_CACHE_LINE_BYTES);
        }
    }
 
  pm->active_bundle = b;
 
error:
  if (err)
    {
      log_err ("%U", format_clib_error, err);
      perfmon_reset (vm);
    }
  return err;
}
 
clib_error_t *
perfmon_start (vlib_main_t *vm, perfmon_bundle_t *b)
{
  clib_error_t *err = 0;
  perfmon_main_t *pm = &perfmon_main;
  int n_groups;
 
  if (pm->is_running == 1)
    return clib_error_return (0, "already running");
 
  if ((err = perfmon_set (vm, b)) != 0)
    return err;
 
  n_groups = vec_len (pm->group_fds);
 
  for (int i = 0; i < n_groups; i++)
    {
      if (ioctl (pm->group_fds[i], PERF_EVENT_IOC_ENABLE,
                 PERF_IOC_FLAG_GROUP) == -1)
        {
          perfmon_reset (vm);
          return clib_error_return_unix (0, "ioctl(PERF_EVENT_IOC_ENABLE)");
        }
    }
  if (b->type == PERFMON_BUNDLE_TYPE_NODE)
    {
 
      vlib_node_function_t *funcs[PERFMON_OFFSET_TYPE_MAX];
#define _(type, pfunc) funcs[type] = pfunc;
 
      foreach_permon_offset_type
#undef _
 
        ASSERT (funcs[b->offset_type]);
 
      for (int i = 0; i < vlib_get_n_threads (); i++)
        vlib_node_set_dispatch_wrapper (vlib_get_main_by_index (i),
                                        funcs[b->offset_type]);
    }
 
  pm->sample_time = vlib_time_now (vm);
  pm->is_running = 1;
 
  return 0;
}
 
clib_error_t *
perfmon_stop (vlib_main_t *vm)
{
  perfmon_main_t *pm = &perfmon_main;
  int n_groups = vec_len (pm->group_fds);
 
  if (pm->is_running != 1)
    return clib_error_return (0, "not running");
 
  if (pm->active_bundle->type == PERFMON_BUNDLE_TYPE_NODE)
    {
      for (int i = 0; i < vlib_get_n_threads (); i++)
        vlib_node_set_dispatch_wrapper (vlib_get_main_by_index (i), 0);
    }
 
  for (int i = 0; i < n_groups; i++)
    {
      if (ioctl (pm->group_fds[i], PERF_EVENT_IOC_DISABLE,
                 PERF_IOC_FLAG_GROUP) == -1)
        {
          perfmon_reset (vm);
          return clib_error_return_unix (0, "ioctl(PERF_EVENT_IOC_DISABLE)");
        }
    }
 
  pm->is_running = 0;
  pm->sample_time = vlib_time_now (vm) - pm->sample_time;
  return 0;
}
 
static clib_error_t *
perfmon_init (vlib_main_t *vm)
{
  perfmon_main_t *pm = &perfmon_main;
  perfmon_source_t *s = pm->sources;
  perfmon_bundle_t *b = pm->bundles;
 
  pm->source_by_name = hash_create_string (0, sizeof (uword));
  while (s)
    {
      clib_error_t *err;
      if (hash_get_mem (pm->source_by_name, s->name) != 0)
        clib_panic ("duplicate source name '%s'", s->name);
      if (s->init_fn && ((err = (s->init_fn) (vm, s))))
        {
          log_warn ("skipping source '%s' - %U", s->name, format_clib_error,
                    err);
          clib_error_free (err);
          s = s->next;
          continue;
        }
 
      hash_set_mem (pm->source_by_name, s->name, s);
      log_debug ("source '%s' regisrtered", s->name);
      s = s->next;
    }
 
  pm->bundle_by_name = hash_create_string (0, sizeof (uword));
  while (b)
    {
      clib_error_t *err;
      uword *p;
      if (hash_get_mem (pm->bundle_by_name, b->name) != 0)
        clib_panic ("duplicate bundle name '%s'", b->name);
 
      if ((p = hash_get_mem (pm->source_by_name, b->source)) == 0)
        {
          log_debug ("missing source '%s', skipping bundle '%s'", b->source,
                     b->name);
          b = b->next;
          continue;
        }
 
      b->src = (perfmon_source_t *) p[0];
      if (b->init_fn && ((err = (b->init_fn) (vm, b))))
        {
          log_warn ("skipping bundle '%s' - %U", b->name, format_clib_error,
                    err);
          clib_error_free (err);
          b = b->next;
          continue;
        }
 
      hash_set_mem (pm->bundle_by_name, b->name, b);
      log_debug ("bundle '%s' regisrtered", b->name);
 
      b = b->next;
    }
 
  return 0;
}
 
VLIB_INIT_FUNCTION (perfmon_init);