Trace IMC (In-Memory collection counters) in powerpc is useful for application level profiling. For trace_imc, presently task context (task_ctx_nr) is set to perf_hw_context. But perf_hw_context is to be used for cpu PMU. So for trace_imc, even though it is per thread PMU, it is preferred to use sw_context inorder to be able to do application level monitoring. Hence change the task_ctx_nr to use perf_sw_context.
Fixes: 012ae244845f ("powerpc/perf: Trace imc PMU functions") Signed-off-by: Athira Rajeev <atraj...@linux.vnet.ibm.com> Reviewed-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com> --- Changelog: v1 -> v2: Added comment in code on why perf_sw_context is used. Notes: trace_imc_event_init currently uses context as perf_hw_context. But ideally there can only be a single PMU for perf_hw_context events which is core PMU. Reference: commit 26657848502b ("perf/core: Verify we have a single perf_hw_context PMU") Reason for using "perf_sw_context" instead of invalid_context is that, task level monitoring is restricted with invalid_context. arch/powerpc/perf/imc-pmu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index e106909ff9c3..8fe57601e61d 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -1457,7 +1457,13 @@ static int trace_imc_event_init(struct perf_event *event) event->hw.idx = -1; - event->pmu->task_ctx_nr = perf_hw_context; + /* + * There can only be a single PMU for + * perf_hw_context events which is assigned + * to core PMU. Hence use "perf_sw_context" for + * trace_imc. + */ + event->pmu->task_ctx_nr = perf_sw_context; event->destroy = reset_global_refc; return 0; } -- 2.33.0