On Fri, Jan 3, 2014 at 6:48 AM, Yan, Zheng <[email protected]> wrote: > Later patch will use it to decide if the LBR stack should be saved/restored > You should describe better what this patch does. It should be repeated from the patch title at least.
> Signed-off-by: Yan, Zheng <[email protected]> > --- > arch/x86/kernel/cpu/perf_event_intel_lbr.c | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c > b/arch/x86/kernel/cpu/perf_event_intel_lbr.c > index bdd8758..2137a9f 100644 > --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c > +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c > @@ -201,15 +201,27 @@ void intel_pmu_lbr_sched_task(struct perf_event_context > *ctx, bool sched_in) > intel_pmu_lbr_reset(); > } > > +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; > > + cpuc = &__get_cpu_var(cpu_hw_events); > + task_ctx = event->ctx ? event->ctx->task_ctx_data : NULL; > + > cpuc->br_sel = event->hw.branch_reg.reg; > > + if (branch_user_callstack(cpuc->br_sel)) > + task_ctx->lbr_callstack_users++; > + > cpuc->lbr_users++; > if (cpuc->lbr_users == 1) > perf_sched_cb_enable(event->ctx->pmu); > @@ -217,11 +229,18 @@ void intel_pmu_lbr_enable(struct perf_event *event) > > void intel_pmu_lbr_disable(struct perf_event *event) > { > - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); > + struct cpu_hw_events *cpuc; > + struct x86_perf_task_context *task_ctx; > > if (!x86_pmu.lbr_nr) > return; > > + cpuc = &__get_cpu_var(cpu_hw_events); > + task_ctx = event->ctx ? event->ctx->task_ctx_data : NULL; > + > + if (branch_user_callstack(cpuc->br_sel)) > + task_ctx->lbr_callstack_users--; > + > cpuc->lbr_users--; > WARN_ON_ONCE(cpuc->lbr_users < 0); > > -- > 1.8.4.2 > -- 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/
