[Patch v1 02/10] perf/x86: add flags to event constraints

Stephane Eranian
2012-10-29T15:19:30Z

This patch adds a flags field to each event constraint.
It can be used to store event specific features which can
then later be used by scheduling code or low-level x86 code.

The flags are propagated into event->hw.flags during the
get_event_constraint() call. They are cleared during the
put_event_constraint() call.

This mechanism is going to be used by the PEBS-LL patches.
It avoids defining yet another table to hold event specific
information.

Signed-off-by: Stephane Eranian <eranian@google.com>
---
arch/x86/kernel/cpu/perf_event.c | 2 +-
arch/x86/kernel/cpu/perf_event.h | 8 +++++---
arch/x86/kernel/cpu/perf_event_intel.c | 5 ++++-
arch/x86/kernel/cpu/perf_event_intel_ds.c | 4 +++-
arch/x86/kernel/cpu/perf_event_intel_uncore.c | 2 +-
include/linux/perf_event.h | 1 +
6 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 7c30b4c..9b56c20 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1470,7 +1470,7 @@ static int __init init_hw_perf_events(void)

unconstrained = (struct event_constraint)
__EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_counters) - 1,
- 0, x86_pmu.num_counters, 0);
+ 0, x86_pmu.num_counters, 0, 0);

x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
x86_pmu_format_group.attrs = x86_pmu.format_attrs;
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 41479da..f78d6e8 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -59,6 +59,7 @@ struct event_constraint {
u64 cmask;
int weight;
int overlap;
+ int flags;
};

struct amd_nb {
@@ -170,16 +171,17 @@ struct cpu_hw_events {
void *kfree_on_online;
};

-#define __EVENT_CONSTRAINT(c, n, m, w, o) {\
+#define __EVENT_CONSTRAINT(c, n, m, w, o, f) {\
{ .idxmsk64 = (n) }, \
.code = (c), \
.cmask = (m), \
.weight = (w), \
.overlap = (o), \
+ .flags = f, \
}

#define EVENT_CONSTRAINT(c, n, m) \
- __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 0)
+ __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 0, 0)

/*
* The overlap flag marks event constraints with overlapping counter
@@ -203,7 +205,7 @@ struct cpu_hw_events {
* and its counter masks must be kept at a minimum.
*/
#define EVENT_CONSTRAINT_OVERLAP(c, n, m) \
- __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 1)
+ __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 1, 0)

/*
* Constraint on the Event code.
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 93b9e11..57d6527 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1367,8 +1367,10 @@ x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)

if (x86_pmu.event_constraints) {
for_each_event_constraint(c, x86_pmu.event_constraints) {
- if ((event->hw.config & c->cmask) == c->code)
+ if ((event->hw.config & c->cmask) == c->code) {
+ event->hw.flags |= c->flags;
return c;
+ }
}
}

@@ -1413,6 +1415,7 @@ intel_put_shared_regs_event_constraints(struct cpu_hw_events *cpuc,
static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
struct perf_event *event)
{
+ event->hw.flags = 0;
intel_put_shared_regs_event_constraints(cpuc, event);
}

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 826054a..f30d85b 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -430,8 +430,10 @@ 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 ((event->hw.config & c->cmask) == c->code) {
+ event->hw.flags |= c->flags;
return c;
+ }
}
}

diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index 3cf3d97..cc39e64 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -2438,7 +2438,7 @@ static int __init uncore_type_init(struct intel_uncore_type *type)

type->unconstrainted = (struct event_constraint)
__EVENT_CONSTRAINT(0, (1ULL << type->num_counters) - 1,
- 0, type->num_counters, 0);
+ 0, type->num_counters, 0, 0);

for (i = 0; i < type->num_boxes; i++) {
pmus[i].func_id = -1;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 6bfb2faa..484cfbc 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -128,6 +128,7 @@ struct hw_perf_event {
int event_base_rdpmc;
int idx;
int last_cpu;
+ int flags;

struct hw_perf_event_extra extra_reg;
struct hw_perf_event_extra branch_reg;
--
1.7.9.5