6.13-stable review patch. If anyone has any objections, please let me know.
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From: Dapeng Mi dapeng1.mi@linux.intel.com
[ Upstream commit b74683b3bb224eccb644cf260753dfc82e802d92 ]
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: 1e53e9d1787b ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/arch/x86/util/topdown.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/arch/x86/util/topdown.c b/tools/perf/arch/x86/util/topdown.c index f63747d0abdf9..d1c6548390496 100644 --- a/tools/perf/arch/x86/util/topdown.c +++ b/tools/perf/arch/x86/util/topdown.c @@ -81,7 +81,7 @@ bool arch_topdown_sample_read(struct evsel *leader) */ evlist__for_each_entry(leader->evlist, evsel) { if (evsel->core.leader != leader->core.leader) - return false; + continue; if (evsel != leader && arch_is_topdown_metrics(evsel)) return true; }