RE: [PATCH V7 00/17] perf, x86: Haswell LBR call stack support

[Liang, Kan]

>> 
> 
> So if I take all except 11,13,16,17 but instead do something like the below,
> everything will work just fine, right?
> 
> Or am I missing something?
> 

Yes, it should work.  Then LBR callstack will rely on user to enable it.
But user never get the LBR callstack data if it's available.  
I'm not sure why you do that? 


> ---
>  arch/x86/kernel/cpu/perf_event.h           |    8 --------
>  arch/x86/kernel/cpu/perf_event_intel_lbr.c |    8 ++++----
>  include/uapi/linux/perf_event.h            |   16 ++++++++--------
>  3 files changed, 12 insertions(+), 20 deletions(-)
> 
> --- a/arch/x86/kernel/cpu/perf_event.h
> +++ b/arch/x86/kernel/cpu/perf_event.h
> @@ -521,14 +521,6 @@ struct x86_perf_task_context {
>  	int lbr_stack_state;
>  };
> 
> -enum {
> -	PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT =
> PERF_SAMPLE_BRANCH_MAX_SHIFT,
> -	PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE,
> -
> -	PERF_SAMPLE_BRANCH_CALL_STACK =
> -				1U <<
> PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT,
> -};
> -
>  #define x86_add_quirk(func_)						\
>  do {									\
>  	static struct x86_pmu_quirk __quirk __initdata = {		\
> --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> @@ -537,7 +537,7 @@ static int intel_pmu_setup_hw_lbr_filter
>  	u64 mask = 0, v;
>  	int i;
> 
> -	for (i = 0; i < PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE; i++) {
> +	for (i = 0; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) {
>  		if (!(br_type & (1ULL << i)))
>  			continue;
> 
> @@ -808,7 +808,7 @@ intel_pmu_lbr_filter(struct cpu_hw_event
>  /*
>   * Map interface branch filters onto LBR filters
>   */
> -static const int
> nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE] = {
> +static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT]
> = {
>  	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= LBR_ANY,
>  	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= LBR_USER,
>  	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= LBR_KERNEL,
> @@ -827,7 +827,7 @@ static const int nhm_lbr_sel_map[PERF_SA
>  	[PERF_SAMPLE_BRANCH_COND_SHIFT]     = LBR_JCC,
>  };
> 
> -static const int
> snb_lbr_sel_map[PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE] = {
> +static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] =
> {
>  	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= LBR_ANY,
>  	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= LBR_USER,
>  	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= LBR_KERNEL,
> @@ -839,7 +839,7 @@ static const int snb_lbr_sel_map[PERF_SA
>  	[PERF_SAMPLE_BRANCH_COND_SHIFT]		= LBR_JCC,
>  };
> 
> -static const int
> hsw_lbr_sel_map[PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE] = {
> +static const int hsw_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX_SHIFT] =
> {
>  	[PERF_SAMPLE_BRANCH_ANY_SHIFT]		= LBR_ANY,
>  	[PERF_SAMPLE_BRANCH_USER_SHIFT]		= LBR_USER,
>  	[PERF_SAMPLE_BRANCH_KERNEL_SHIFT]	= LBR_KERNEL,
> --- a/include/uapi/linux/perf_event.h
> +++ b/include/uapi/linux/perf_event.h
> @@ -166,6 +166,8 @@ enum perf_branch_sample_type_shift {
>  	PERF_SAMPLE_BRANCH_NO_TX_SHIFT		= 9, /* not
> in transaction */
>  	PERF_SAMPLE_BRANCH_COND_SHIFT		= 10, /* conditional
> branches */
> 
> +	PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT	= 11, /* call/ret
> stack */
> +
>  	PERF_SAMPLE_BRANCH_MAX_SHIFT		/* non-ABI */
>  };
> 
> @@ -175,18 +177,16 @@ enum perf_branch_sample_type {
>  	PERF_SAMPLE_BRANCH_HV		= 1U <<
> PERF_SAMPLE_BRANCH_HV_SHIFT,
> 
>  	PERF_SAMPLE_BRANCH_ANY		= 1U <<
> PERF_SAMPLE_BRANCH_ANY_SHIFT,
> -	PERF_SAMPLE_BRANCH_ANY_CALL	=
> -				1U <<
> PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT,
> -	PERF_SAMPLE_BRANCH_ANY_RETURN	=
> -				1U <<
> PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT,
> -	PERF_SAMPLE_BRANCH_IND_CALL	=
> -				1U <<
> PERF_SAMPLE_BRANCH_IND_CALL_SHIFT,
> -	PERF_SAMPLE_BRANCH_ABORT_TX	=
> -				1U <<
> PERF_SAMPLE_BRANCH_ABORT_TX_SHIFT,
> +	PERF_SAMPLE_BRANCH_ANY_CALL	= 1U <<
> PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT,
> +	PERF_SAMPLE_BRANCH_ANY_RETURN	= 1U <<
> PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT,
> +	PERF_SAMPLE_BRANCH_IND_CALL	= 1U <<
> PERF_SAMPLE_BRANCH_IND_CALL_SHIFT,
> +	PERF_SAMPLE_BRANCH_ABORT_TX	= 1U <<
> PERF_SAMPLE_BRANCH_ABORT_TX_SHIFT,
>  	PERF_SAMPLE_BRANCH_IN_TX	= 1U <<
> PERF_SAMPLE_BRANCH_IN_TX_SHIFT,
>  	PERF_SAMPLE_BRANCH_NO_TX	= 1U <<
> PERF_SAMPLE_BRANCH_NO_TX_SHIFT,
>  	PERF_SAMPLE_BRANCH_COND		= 1U <<
> PERF_SAMPLE_BRANCH_COND_SHIFT,
> 
> +	PERF_SAMPLE_BRANCH_CALL_STACK	= 1U <<
> PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT,
> +
>  	PERF_SAMPLE_BRANCH_MAX		= 1U <<
> PERF_SAMPLE_BRANCH_MAX_SHIFT,
>  };
> 
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