On Mon, Mar 11, 2024 at 6:19 PM Pu Lehui <pulehui@xxxxxxxxxxxxxxx> wrote: > > From: Pu Lehui <pulehui@xxxxxxxxxx> > > RISC-V perf driver does not yet support branch sampling. Although the > specification is in the works [0], it is best to disable such events > until support is available, otherwise we will get unexpected results. > Due to this reason, two riscv bpf testcases get_branch_snapshot and > perf_branches/perf_branches_hw fail. > > Link: https://github.com/riscv/riscv-control-transfer-records [0] > Fixes: f5bfa23f576f ("RISC-V: Add a perf core library for pmu drivers") > Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx> > --- > drivers/perf/riscv_pmu.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c > index c78a6fd6c57f..b4efdddb2ad9 100644 > --- a/drivers/perf/riscv_pmu.c > +++ b/drivers/perf/riscv_pmu.c > @@ -313,6 +313,10 @@ static int riscv_pmu_event_init(struct perf_event *event) > u64 event_config = 0; > uint64_t cmask; > > + /* driver does not support branch stack sampling */ > + if (has_branch_stack(event)) > + return -EOPNOTSUPP; > + > hwc->flags = 0; > mapped_event = rvpmu->event_map(event, &event_config); > if (mapped_event < 0) { > -- > 2.34.1 > Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx> -- Regards, Atish
