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When running topdown leader smapling test on Intel hybrid platforms,
such as LNL/ARL, we see the below error.
Topdown leader sampling test
Topdown leader sampling [Failed topdown events not reordered correctly]
It indciates the below command fails.
perf record -o "${perfdata}" -e "{instructions,slots,topdown-retiring}:S" true
The root cause is that perf tool creats a perf event for each PMU type
if it can create.
As for this command, there would be 5 perf events created,
cpu_atom/instructions/,cpu_atom/topdown_retiring/,
cpu_core/slots/,cpu_core/instructions/,cpu_core/topdown-retiring/
For these 5 events, the 2 cpu_atom events are in a group and the other 3
cpu_core events are in another group.
When arch_topdown_sample_read() traverses all these 5 events, events
cpu_atom/instructions/ and cpu_core/slots/ don't have a same group
leade, and then return false directly and lead to cpu_core/slots/ event
is used to sample and this is not allowed by PMU driver.
It's a overkill to return false directly if "evsel->core.leader !=
leader->core.leader" since there could be multiple groups in the event
list.
Just "continue" instead of "return false" to fix this issue.
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.