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SubjectRe: [PATCH 05/22] perf/x86: Support constraint ranges
On Mon, Mar 18, 2019 at 02:41:27PM -0700, kan.liang@linux.intel.com wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> Icelake extended the general counters to 8, even when SMT is enabled.
> However only a (large) subset of the events can be used on all 8
> counters.
>
> The events that can or cannot be used on all counters are organized
> in ranges.
>
> We need a lot of scheduler constraints to handle all this.
>
> To avoid blowing up the tables add event code ranges to the constraint
> tables, and a new inline function to match them.
>
> The changes costs ~2k text size according to 0day report.

Where?! there isn't much code here.

> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
> ---
> arch/x86/events/intel/core.c | 2 +-
> arch/x86/events/intel/ds.c | 2 +-
> arch/x86/events/perf_event.h | 34 ++++++++++++++++++++++++++++++++++
> 3 files changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index a964b9832b0c..8486ab87f8f8 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c
> @@ -2655,7 +2655,7 @@ x86_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
>
> if (x86_pmu.event_constraints) {
> for_each_event_constraint(c, x86_pmu.event_constraints) {
> - if ((event->hw.config & c->cmask) == c->code) {
> + if (constraint_match(c, event->hw.config)) {
> event->hw.flags |= c->flags;
> return c;
> }
> diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
> index 974284c5ed6c..30370fb93e21 100644
> --- a/arch/x86/events/intel/ds.c
> +++ b/arch/x86/events/intel/ds.c
> @@ -858,7 +858,7 @@ struct event_constraint *intel_pebs_constraints(struct perf_event *event)
>
> if (x86_pmu.pebs_constraints) {
> for_each_event_constraint(c, x86_pmu.pebs_constraints) {
> - if ((event->hw.config & c->cmask) == c->code) {
> + if (constraint_match(c, event->hw.config)) {
> event->hw.flags |= c->flags;
> return c;
> }
> @@ -71,6 +72,12 @@ struct event_constraint {
> #define PERF_X86_EVENT_AUTO_RELOAD 0x0400 /* use PEBS auto-reload */
> #define PERF_X86_EVENT_LARGE_PEBS 0x0800 /* use large PEBS */
>
> +static inline bool constraint_match(struct event_constraint *c, u64 ecode)
> +{
> + ecode &= c->cmask;
> + return ecode == c->code ||
> + (c->range_end && ecode >= c->code && ecode <= c->range_end);
> +}
>
> struct amd_nb {
> int nb_id; /* NorthBridge id */

That's all the code, how does that add up to 2k ?

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