From: Kan Liang kan.liang@linux.intel.com
[The patch set is to fix the perf top failure on all Intel hybrid machines. Without the patch, the default perf top command is broken.
I have verified that the patches on both stable 6.6 and 6.7. They can be applied to stable 6.6 and 6.7 tree without any modification as well.
Please consider to apply them to stable 6.6 and 6.7. Thanks]
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From: Kan Liang kan.liang@linux.intel.com
[ Upstream commit 5fa695e7da4975e8d21ce49f3718d6cf00ecb75e ]
perf top errors out on a hybrid machine $perf top
Error: The cycles:P event is not supported.
The perf top expects that the "cycles" is collected on all CPUs in the system. But for hybrid there is no single "cycles" event which can cover all CPUs. Perf has to split it into two cycles events, e.g., cpu_core/cycles/ and cpu_atom/cycles/. Each event has its own CPU mask. If a event is opened on the unsupported CPU. The open fails. That's the reason of the above error out.
Perf should only open the cycles event on the corresponding CPU. The commit ef91871c960e ("perf evlist: Propagate user CPU maps intersecting core PMU maps") intersect the requested CPU map with the CPU map of the PMU. Use the evsel's cpus to replace user_requested_cpus.
The evlist's threads are also propagated to the evsel's threads in __perf_evlist__propagate_maps(). For a system-wide event, perf appends a dummy event and assign it to the evsel's threads. For a per-thread event, the evlist's thread_map is assigned to the evsel's threads. The same as the other tools, e.g., perf record, using the evsel's threads when opening an event.
Reported-by: Arnaldo Carvalho de Melo acme@kernel.org Reviewed-by: Ian Rogers irogers@google.com Signed-off-by: Kan Liang kan.liang@linux.intel.com Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Hector Martin marcan@marcan.st Cc: Marc Zyngier maz@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Closes: https://lore.kernel.org/linux-perf-users/ZXNnDrGKXbEELMXV@kernel.org/ Link: https://lore.kernel.org/r/20231214144612.1092028-1-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- tools/perf/builtin-top.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index ea8c7eca5eee..cce9350177e2 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1027,8 +1027,8 @@ static int perf_top__start_counters(struct perf_top *top)
evlist__for_each_entry(evlist, counter) { try_again: - if (evsel__open(counter, top->evlist->core.user_requested_cpus, - top->evlist->core.threads) < 0) { + if (evsel__open(counter, counter->core.cpus, + counter->core.threads) < 0) {
/* * Specially handle overwrite fall back.