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Dapeng Mi
b74683b3bb
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: 1e53e9d178 ("perf x86/topdown: Correct leader selection with sample_read enabled")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Tested-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250307023906.1135613-2-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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