bperf restricts the size of perf_attr_map's entries to 16, which cannot hold all events in many scenarios. A typical example is when the user specifies `-a -ddd` ([0]). And in other cases such as top-down analysis, which often requires a set of more than 16 PMUs to be collected simultaneously. Fix this by increase perf_attr_map entries to 100, and an event number check has been introduced when bperf__load() to ensure that users receive a more friendly prompt when the event limit is reached. [0] https://lore.kernel.org/all/20230104064402.1551516-3-namhyung@xxxxxxxxxx/ Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF") Signed-off-by: Tengda Wu <wutengda@xxxxxxxxxxxxxxx> --- tools/perf/util/bpf_counter.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c index 7a8af60e0f51..3346129c20cf 100644 --- a/tools/perf/util/bpf_counter.c +++ b/tools/perf/util/bpf_counter.c @@ -28,7 +28,7 @@ #include "bpf_skel/bperf_leader.skel.h" #include "bpf_skel/bperf_follower.skel.h" -#define ATTR_MAP_SIZE 16 +#define ATTR_MAP_SIZE 100 static inline void *u64_to_ptr(__u64 ptr) { @@ -451,6 +451,12 @@ static int bperf__load(struct evsel *evsel, struct target *target) enum bperf_filter_type filter_type; __u32 filter_entry_cnt, i; + if (evsel->evlist->core.nr_entries > ATTR_MAP_SIZE) { + pr_err("Too many events, please limit to %d or less\n", + ATTR_MAP_SIZE); + return -1; + } + if (bperf_check_target(evsel, target, &filter_type, &filter_entry_cnt)) return -1; -- 2.34.1
