The tests for the
[intel-pt](3483740289/lldb/docs/use/intel_pt.rst)
trace plugin were failing for multiple reasons.
On machines where tracing is supported many of the tests were crashing
because of a nullptr dereference. It looks like the `core_file`
parameter in `ProcessTrace::CreateInstance` was once ignored, but was
changed to always being dereferenced. This caused the tests to fail even
when tracing was supported.
On machines where tracing is not supported we would still run tests that
attempt to take a trace. These would obviously fail because the required
hardware is not present. Note that some of the tests simply read
serialized json as trace files which does not require any special
hardware.
This PR fixes these two issues by guarding the pointer dereference and
then skipping unsupported tests on machines. With these changes the
trace tests pass on both types of machines.
We also add a new unit test to validate that a process can be created
with a nullptr core_file through the generic process trace plugin path.
from PEP8
(https://peps.python.org/pep-0008/#programming-recommendations):
> Comparisons to singletons like None should always be done with is or
is not, never the equality operators.
Co-authored-by: Eisuke Kawashima <e-kwsm@users.noreply.github.com>
This is an ongoing series of commits that are reformatting our Python
code. Reformatting is done with `black` (23.1.0).
If you end up having problems merging this commit because you have made
changes to a python file, the best way to handle that is to run `git
checkout --ours <yourfile>` and then reformat it with black.
RFC: https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Differential revision: https://reviews.llvm.org/D151460
A trace bundle contains many trace files, and, in the case of intel pt, the
largest files are often the context switch traces because they are not
compressed by default. As a way to improve this, I'm adding a --compact option
to the `trace save` command that filters out unwanted processes from the
context switch traces. Eventually we can do the same for intel pt traces as
well.
Differential Revision: https://reviews.llvm.org/D129239
Add trace load functionality to SBDebugger via the `LoadTraceFromFile` method.
Update intelpt test case class to have `testTraceLoad` method so we can take advantage of
the testApiAndSB decorator to test both the CLI and SB without duplicating code.
Differential Revision: https://reviews.llvm.org/D128107
As discusses offline with @jj10305, we are updating some naming used throughout the code, specially in the json schema
- traceBuffer -> iptTrace
- core -> cpu
Differential Revision: https://reviews.llvm.org/D127817
This diffs implements per-core tracing on lldb-server. It also includes tests that ensure that tracing can be initiated from the client and that the jLLDBGetState ppacket returns the list of trace buffers per core.
This doesn't include any decoder changes.
Finally, this makes some little changes here and there improving the existing code.
A specific piece of code that can't reliably be tested is when tracing
per core fails due to permissions. In this case we add a
troubleshooting message and this is the manual test:
```
/proc/sys/kernel/perf_event_paranoid set to 1
(lldb) process trace start --per-core-tracing error: perf event syscall failed: Permission denied
You might need that /proc/sys/kernel/perf_event_paranoid has a value of 0 or -1.
``
Differential Revision: https://reviews.llvm.org/D124858
This updates the documentation of the gdb-remote protocol, as well as the help messages, to include the new --per-core-tracing option.
Differential Revision: https://reviews.llvm.org/D124640
This adds a basic SB API for creating and stopping traces.
Note: This doesn't add any APIs for inspecting individual instructions. That'd be a more complicated change and it might be better to enhande the dump functionality to output the data in binary format. I'll leave that for a later diff.
This also enhances the existing tests so that they test the same flow using both the command interface and the SB API.
I also did some cleanup of legacy code.
Differential Revision: https://reviews.llvm.org/D103500
