| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #ifndef SRC_PROFILING_PERF_EVENT_CONFIG_H_ |
| #define SRC_PROFILING_PERF_EVENT_CONFIG_H_ |
| |
| #include <linux/perf_event.h> |
| #include <stdint.h> |
| #include <sys/types.h> |
| |
| #include "perfetto/ext/base/optional.h" |
| #include "perfetto/tracing/core/data_source_config.h" |
| #include "src/profiling/perf/unwind_support.h" |
| |
| #include "protos/perfetto/config/profiling/perf_event_config.pbzero.h" |
| |
| namespace perfetto { |
| namespace profiling { |
| |
| // Describes a single profiling configuration. Bridges the gap between the data |
| // source config proto, and the raw "perf_event_attr" structs to pass to the |
| // perf_event_open syscall. |
| // TODO(rsavitski): make sampling conditional? Or should we always go through |
| // the sampling interface for simplicity? Reads can be done on-demand even if |
| // sampling is on. So the question becomes whether we need *only* on-demand |
| // reads. |
| class EventConfig { |
| public: |
| static base::Optional<EventConfig> Create(const DataSourceConfig& ds_config) { |
| protos::pbzero::PerfEventConfig::Decoder pb_config( |
| ds_config.perf_event_config_raw()); |
| |
| return EventConfig(pb_config); |
| } |
| |
| uint32_t target_cpu() const { return target_cpu_; } |
| |
| perf_event_attr* perf_attr() const { |
| return const_cast<perf_event_attr*>(&perf_event_attr_); |
| } |
| |
| private: |
| EventConfig(const protos::pbzero::PerfEventConfig::Decoder&) { |
| auto& pe = perf_event_attr_; |
| memset(&pe, 0, sizeof(perf_event_attr)); |
| pe.size = sizeof(perf_event_attr); |
| |
| pe.exclude_kernel = true; |
| pe.disabled = false; |
| |
| // Ask the kernel to tune sampling period to get ~100 Hz. |
| pe.type = PERF_TYPE_SOFTWARE; |
| pe.config = PERF_COUNT_SW_CPU_CLOCK; |
| pe.sample_freq = 100; |
| pe.freq = true; |
| |
| pe.sample_type = |
| PERF_SAMPLE_TID | PERF_SAMPLE_STACK_USER | PERF_SAMPLE_REGS_USER; |
| // Needs to be < ((u16)(~0u)), and have bottom 8 bits clear. |
| pe.sample_stack_user = (1u << 15); |
| pe.sample_regs_user = PerfUserRegsMaskForCurrentArch(); |
| } |
| |
| // TODO(rsavitski): for now hardcode each session to be for a single cpu's |
| // scope. In general a config will correspond to N cpus and/or tids. |
| uint32_t target_cpu_ = 0; |
| |
| // TODO(rsavitski): if we allow for event groups containing multiple sampled |
| // counters, we'll need to vary the .type & .config fields per |
| // perf_event_open. |
| perf_event_attr perf_event_attr_; |
| }; |
| |
| } // namespace profiling |
| } // namespace perfetto |
| |
| #endif // SRC_PROFILING_PERF_EVENT_CONFIG_H_ |