Refactor the command option enum values and the command argument table
to connect the two. This has two benefits:
- We guarantee that two options that use the same argument type have
the same accepted values.
- We can print the enum values and their description in the help
output. (D129707)
Differential revision: https://reviews.llvm.org/D129703
We want to include events with metadata, like context switches, and this
requires the API to handle events with payloads (e.g. information about
such context switches). Besides this, we want to support multiple
similar events between two consecutive instructions, like multiple
context switches. However, the current implementation is not good for this because
we are defining events as bitmask enums associated with specific
instructions. Thus, we need to decouple instructions from events and
make events actual items in the trace, just like instructions and
errors.
- Add accessors in the TraceCursor to know if an item is an event or not
- Modify from the TraceDumper all the way to DecodedThread to support
- Renamed the paused event to disabled.
- Improved the tsc handling logic. I was using an API for getting the tsc from libipt, but that was an overkill that should be used when not processing events manually, but as we are already processing events, we can more easily get the tscs.
event items. Fortunately this simplified many things
- As part of this refactor, I also fixed and long stating issue, which is that some non decoding errors were being inserted in the decoded thread. I changed this so that TraceIntelPT::Decode returns an error if the decoder couldn't be set up proplerly. Then, errors within a trace are actual anomalies found in between instrutions.
All test pass
Differential Revision: https://reviews.llvm.org/D128576
This diff introduces Hierarchical Trace Representation (HTR) and creates the `thread trace export ctf -f <filename> -t <thread_id>` command to export an Intel PT trace's HTR to Chrome Trace Format (CTF) for visualization.
See `lldb/docs/htr.rst` for context/documentation on HTR.
**Overview of Changes**
- Add HTR documentation (see `lldb/docs/htr.rst`)
- Add HTR structures (layer, block, block metadata)
- Implement "Basic Super Block" HTR pass
- Add 'thread trace export ctf' command to export the HTR of an Intel PT
trace to Chrome Trace Format (CTF)
As this diff is the first iteration of HTR and trace visualization, future diffs will build on this work by generalizing the internal design of HTR and implementing new HTR passes that provide better trace summarization/visualization.
See attached video for an example of Intel PT trace visualization:
{F17851042}
Original Author: jj10306
Submitted by: wallace
Reviewed By: wallace, clayborg
Differential Revision: https://reviews.llvm.org/D105741
This diff introduces Hierarchical Trace Representation (HTR) and creates the `thread trace export ctf -f <filename> -t <thread_id>` command to export an Intel PT trace's HTR to Chrome Trace Format (CTF) for visualization.
See `lldb/docs/htr.rst` for context/documentation on HTR.
**Overview of Changes**
- Add HTR documentation (see `lldb/docs/htr.rst`)
- Add HTR structures (layer, block, block metadata)
- Implement "Basic Super Block" HTR pass
- Add 'thread trace export ctf' command to export the HTR of an Intel PT
trace to Chrome Trace Format (CTF)
As this diff is the first iteration of HTR and trace visualization, future diffs will build on this work by generalizing the internal design of HTR and implementing new HTR passes that provide better trace summarization/visualization.
See attached video for an example of Intel PT trace visualization:
{F17851042}
Original Author: jj10306
Submitted by: wallace
Reviewed By: wallace, clayborg
Differential Revision: https://reviews.llvm.org/D105741
Copying from the inline documentation:
```
Trace exporter plug-ins operate on traces, converting the trace data provided by an \a lldb_private::TraceCursor into a different format that can be digested by other tools, e.g. Chrome Trace Event Profiler.
Trace exporters are supposed to operate on an architecture-agnostic fashion, as a TraceCursor, which feeds the data, hides the actual trace technology being used.
```
I want to use this to make the code in https://reviews.llvm.org/D105741 a plug-in. I also imagine that there will be more and more exporters being implemented, as an exporter creates something useful out of trace data. And tbh I don't want to keep adding more stuff to the lldb/Target folder.
This is the minimal definition for a TraceExporter plugin. I plan to use this with the following commands:
- thread trace export <plug-in name> [plug-in specific args]
- This command would support autocompletion of plug-in names
- thread trace export list
- This command would list the available trace exporter plug-ins
I don't plan to create yet a "process trace export" because it's easier to start analyzing the trace of a given thread than of the entire process. When we need a process-level command, we can implement it.
I also don't plan to force each "export" command implementation to support multiple threads (for example, "thread trace start 1 2 3" or "thread trace start all" operate on many threads simultaneously). The reason is that the format used by the exporter might or might not support multiple threads, so I'm leaving this decision to each trace exporter plug-in.
Differential Revision: https://reviews.llvm.org/D106501
Jonas Devlieghere