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-rw-r--r--src/plugins/perfmon/intel/dispatch_wrapper.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/src/plugins/perfmon/intel/dispatch_wrapper.c b/src/plugins/perfmon/intel/dispatch_wrapper.c
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+++ b/src/plugins/perfmon/intel/dispatch_wrapper.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 "vppinfra/string.h"
+#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>
+
+vlib_node_function_t *perfmon_dispatch_wrappers[PERF_MAX_EVENTS + 1];
+
+static_always_inline void
+perfmon_read_pmcs (u64 *counters, u32 *indexes, u8 n_counters)
+{
+ for (int i = 0; i < n_counters; i++)
+ counters[i] = _rdpmc (indexes[i] - 1);
+}
+
+static_always_inline uword
+perfmon_dispatch_wrapper_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
+ vlib_frame_t *frame, u8 n_events)
+{
+ perfmon_main_t *pm = &perfmon_main;
+ perfmon_thread_runtime_t *rt =
+ vec_elt_at_index (pm->thread_runtimes, vm->thread_index);
+ perfmon_node_stats_t *s =
+ vec_elt_at_index (rt->node_stats, node->node_index);
+
+ struct
+ {
+ u64 t[2][PERF_MAX_EVENTS];
+ } samples;
+ uword rv;
+
+ clib_prefetch_load (s);
+
+ perfmon_read_pmcs (&samples.t[0][0], &rt->indexes[0], n_events);
+ rv = node->function (vm, node, frame);
+ perfmon_read_pmcs (&samples.t[1][0], &rt->indexes[0], n_events);
+
+ if (rv == 0)
+ return rv;
+
+ s->n_calls += 1;
+ s->n_packets += rv;
+
+ for (int i = 0; i < n_events; i++)
+ {
+ if (!(rt->preserve_samples & 1 << i))
+ {
+ s->value[i] += samples.t[1][i] - samples.t[0][i];
+ }
+ else
+ {
+ s->t[0].value[i] = samples.t[0][i];
+ s->t[1].value[i] = samples.t[1][i];
+ }
+ }
+
+ return rv;
+}
+
+static_always_inline u32
+perfmon_mmap_read_index (const struct perf_event_mmap_page *mmap_page)
+{
+ u32 idx;
+ u32 seq;
+
+ /* See documentation in /usr/include/linux/perf_event.h, for more details
+ * but the 2 main important things are:
+ * 1) if seq != mmap_page->lock, it means the kernel is currently updating
+ * the user page and we need to read it again
+ * 2) if idx == 0, it means the perf event is currently turned off and we
+ * just need to read the kernel-updated 'offset', otherwise we must also
+ * add the current hw value (hence rdmpc) */
+ do
+ {
+ seq = mmap_page->lock;
+ CLIB_COMPILER_BARRIER ();
+
+ idx = mmap_page->index;
+
+ CLIB_COMPILER_BARRIER ();
+ }
+ while (mmap_page->lock != seq);
+
+ return idx;
+}
+
+static_always_inline clib_error_t *
+read_mmap_indexes (perfmon_bundle_t *b)
+{
+ perfmon_main_t *pm = &perfmon_main;
+ for (int i = 0; i < vec_len (pm->thread_runtimes); i++)
+ {
+ perfmon_thread_runtime_t *tr;
+ tr = vec_elt_at_index (pm->thread_runtimes, i);
+
+ for (int j = 0; j < b->n_events; j++)
+ {
+ tr->indexes[j] = perfmon_mmap_read_index (tr->mmap_pages[j]);
+
+ /* if a zero index is returned generate error */
+ if (!tr->indexes[j])
+ {
+ return clib_error_return (0, "invalid rdpmc index");
+ }
+ }
+ }
+ return 0;
+}
+
+clib_error_t *
+intel_config_dispatch_wrapper (perfmon_bundle_t *b,
+ vlib_node_function_t **dispatch_wrapper)
+{
+ clib_error_t *err = 0;
+ if ((err = read_mmap_indexes (b)) != 0)
+ return err;
+
+ (*dispatch_wrapper) = perfmon_dispatch_wrappers[b->n_events];
+ return 0;
+}
+
+#define foreach_n_events \
+ _ (1) _ (2) _ (3) _ (4) _ (5) _ (6) _ (7) _ (8) _ (9) _ (10) _ (11) _ (12)
+
+#define _(x) \
+ static uword perfmon_dispatch_wrapper##x ( \
+ vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame) \
+ { \
+ return perfmon_dispatch_wrapper_inline (vm, node, frame, x); \
+ }
+
+foreach_n_events
+#undef _
+
+ vlib_node_function_t *perfmon_dispatch_wrappers[PERF_MAX_EVENTS + 1] = {
+#define _(x) [x] = &perfmon_dispatch_wrapper##x,
+ foreach_n_events
+#undef _
+ };