On Wed, Sep 10, 2014 at 10:09:05AM -0400, [email protected] wrote: > @@ -204,9 +204,15 @@ void intel_pmu_lbr_sched_task(struct perf_event_context > *ctx, bool sched_in) > } > } > > +static inline bool branch_user_callstack(unsigned br_sel) > +{ > + return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK); > +} > + > void intel_pmu_lbr_enable(struct perf_event *event) > { > struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); > + struct x86_perf_task_context *task_ctx; > > if (!x86_pmu.lbr_nr) > return; > @@ -220,6 +226,10 @@ void intel_pmu_lbr_enable(struct perf_event *event) > } > cpuc->br_sel = event->hw.branch_reg.reg; > > + task_ctx = event->ctx ? event->ctx->task_ctx_data : NULL; > + if (task_ctx && branch_user_callstack(cpuc->br_sel)) > + task_ctx->lbr_callstack_users++; > +
Does it make sense to flip those conditions to avoid a potentially useless dereference? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
