| //===-- PerfContextSwitchDecoder.h --======----------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_PERFCONTEXTSWITCHDECODER_H |
| #define LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_PERFCONTEXTSWITCHDECODER_H |
| |
| #include "lldb/Utility/TraceIntelPTGDBRemotePackets.h" |
| #include "lldb/lldb-types.h" |
| #include "llvm/Support/Error.h" |
| #include <set> |
| #include <vector> |
| |
| namespace lldb_private { |
| namespace trace_intel_pt { |
| |
| /// This class indicates the time interval in which a thread was running |
| /// continuously on a cpu core. |
| struct ThreadContinuousExecution { |
| |
| /// In most cases both the start and end of a continuous execution can be |
| /// accurately recovered from the context switch trace, but in some cases one |
| /// of these endpoints might be guessed or not known at all, due to contention |
| /// problems in the trace or because tracing was interrupted, e.g. with ioctl |
| /// calls, which causes gaps in the trace. Because of that, we identify which |
| /// situation we fall into with the following variants. |
| enum class Variant { |
| /// Both endpoints are known. |
| Complete, |
| /// The end is known and we have a lower bound for the start, i.e. the |
| /// previous execution in the same cpu happens strictly before the hinted |
| /// start. |
| HintedStart, |
| /// The start is known and we have an upper bound for the end, i.e. the next |
| /// execution in the same cpu happens strictly after the hinted end. |
| HintedEnd, |
| /// We only know the start. This might be the last entry of a cpu trace. |
| OnlyStart, |
| /// We only know the end. This might be the first entry or a cpu trace. |
| OnlyEnd, |
| } variant; |
| |
| /// \return |
| /// The lowest tsc that we are sure of, i.e. not hinted. |
| uint64_t GetLowestKnownTSC() const; |
| |
| /// \return |
| /// The known or hinted start tsc, or 0 if the variant is \a OnlyEnd. |
| uint64_t GetStartTSC() const; |
| |
| /// \return |
| /// The known or hinted end tsc, or max \a uint64_t if the variant is \a |
| /// OnlyStart. |
| uint64_t GetEndTSC() const; |
| |
| /// Constructors for the different variants of this object |
| /// |
| /// \{ |
| static ThreadContinuousExecution |
| CreateCompleteExecution(lldb::cpu_id_t cpu_id, lldb::tid_t tid, |
| lldb::pid_t pid, uint64_t start, uint64_t end); |
| |
| static ThreadContinuousExecution |
| CreateHintedStartExecution(lldb::cpu_id_t cpu_id, lldb::tid_t tid, |
| lldb::pid_t pid, uint64_t hinted_start, |
| uint64_t end); |
| |
| static ThreadContinuousExecution |
| CreateHintedEndExecution(lldb::cpu_id_t cpu_id, lldb::tid_t tid, |
| lldb::pid_t pid, uint64_t start, |
| uint64_t hinted_end); |
| |
| static ThreadContinuousExecution CreateOnlyEndExecution(lldb::cpu_id_t cpu_id, |
| lldb::tid_t tid, |
| lldb::pid_t pid, |
| uint64_t end); |
| |
| static ThreadContinuousExecution |
| CreateOnlyStartExecution(lldb::cpu_id_t cpu_id, lldb::tid_t tid, |
| lldb::pid_t pid, uint64_t start); |
| /// \} |
| |
| union { |
| struct { |
| uint64_t start; |
| uint64_t end; |
| } complete; |
| struct { |
| uint64_t start; |
| } only_start; |
| struct { |
| uint64_t end; |
| } only_end; |
| /// The following 'hinted' structures are useful when there are contention |
| /// problems in the trace |
| struct { |
| uint64_t hinted_start; |
| uint64_t end; |
| } hinted_start; |
| struct { |
| uint64_t start; |
| uint64_t hinted_end; |
| } hinted_end; |
| } tscs; |
| |
| lldb::cpu_id_t cpu_id; |
| lldb::tid_t tid; |
| lldb::pid_t pid; |
| |
| private: |
| /// We keep this constructor private to force the usage of the static named |
| /// constructors. |
| ThreadContinuousExecution(lldb::cpu_id_t cpu_id, lldb::tid_t tid, |
| lldb::pid_t pid) |
| : cpu_id(cpu_id), tid(tid), pid(pid) {} |
| }; |
| |
| /// Decodes a context switch trace collected with perf_event_open. |
| /// |
| /// \param[in] data |
| /// The context switch trace in binary format. |
| /// |
| /// \param[i] cpu_id |
| /// The cpu_id where the trace were gotten from. |
| /// |
| /// \param[in] tsc_conversion |
| /// The conversion values used to confert nanoseconds to TSC. |
| /// |
| /// \return |
| /// A list of continuous executions recovered from the raw trace sorted by |
| /// time, or an \a llvm::Error if the data is malformed. |
| llvm::Expected<std::vector<ThreadContinuousExecution>> |
| DecodePerfContextSwitchTrace(llvm::ArrayRef<uint8_t> data, |
| lldb::cpu_id_t cpu_id, |
| const LinuxPerfZeroTscConversion &tsc_conversion); |
| |
| llvm::Expected<std::vector<uint8_t>> |
| FilterProcessesFromContextSwitchTrace(llvm::ArrayRef<uint8_t> data, |
| const std::set<lldb::pid_t> &pids); |
| |
| } // namespace trace_intel_pt |
| } // namespace lldb_private |
| |
| #endif // LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_PERFCONTEXTSWITCHDECODER_H |