6.6-stable review patch. If anyone has any objections, please let me know.
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From: James Clark james.clark@linaro.org
[ Upstream commit f7e36d02d771ee14acae1482091718460cffb321 ]
Since the linked fixes: commit, specifying a CPU on hybrid platforms results in an error because Perf tries to open an extended type event on "any" CPU which isn't valid. Extended type events can only be opened on CPUs that match the type.
Before (working):
$ perf record --cpu 1 -- true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.385 MB perf.data (7 samples) ]
After (not working):
$ perf record -C 1 -- true WARNING: A requested CPU in '1' is not supported by PMU 'cpu_atom' (CPUs 16-27) for event 'cycles:P' Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cpu_atom/cycles:P/). /bin/dmesg | grep -i perf may provide additional information.
(Ignore the warning message, that's expected and not particularly relevant to this issue).
This is because perf_cpu_map__intersect() of the user specified CPU (1) and one of the PMU's CPUs (16-27) correctly results in an empty (NULL) CPU map. However for the purposes of opening an event, libperf converts empty CPU maps into an any CPU (-1) which the kernel rejects.
Fix it by deleting evsels with empty CPU maps in the specific case where user requested CPU maps are evaluated.
Fixes: 251aa040244a ("perf parse-events: Wildcard most "numeric" events") Reviewed-by: Ian Rogers irogers@google.com Tested-by: Thomas Falcon thomas.falcon@intel.com Signed-off-by: James Clark james.clark@linaro.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Link: https://lore.kernel.org/r/20241114160450.295844-2-james.clark@linaro.org Signed-off-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/perf/evlist.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c index fad607789d1e..00ada8acee61 100644 --- a/tools/lib/perf/evlist.c +++ b/tools/lib/perf/evlist.c @@ -47,6 +47,20 @@ static void __perf_evlist__propagate_maps(struct perf_evlist *evlist, */ perf_cpu_map__put(evsel->cpus); evsel->cpus = perf_cpu_map__intersect(evlist->user_requested_cpus, evsel->own_cpus); + + /* + * Empty cpu lists would eventually get opened as "any" so remove + * genuinely empty ones before they're opened in the wrong place. + */ + if (perf_cpu_map__is_empty(evsel->cpus)) { + struct perf_evsel *next = perf_evlist__next(evlist, evsel); + + perf_evlist__remove(evlist, evsel); + /* Keep idx contiguous */ + if (next) + list_for_each_entry_from(next, &evlist->entries, node) + next->idx--; + } } else if (!evsel->own_cpus || evlist->has_user_cpus || (!evsel->requires_cpu && perf_cpu_map__has_any_cpu(evlist->user_requested_cpus))) { /* @@ -80,11 +94,11 @@ static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
static void perf_evlist__propagate_maps(struct perf_evlist *evlist) { - struct perf_evsel *evsel; + struct perf_evsel *evsel, *n;
evlist->needs_map_propagation = true;
- perf_evlist__for_each_evsel(evlist, evsel) + list_for_each_entry_safe(evsel, n, &evlist->entries, node) __perf_evlist__propagate_maps(evlist, evsel); }