[tip:perf/core] perf, sparc: Implement group scheduling transactional APIs

From: tip-bot for Lin Ming
Date: Tue May 18 2010 - 13:19:18 EST


Commit-ID: a13c3afd9b62b6dace80654964cc4ca7d2db8092
Gitweb: http://git.kernel.org/tip/a13c3afd9b62b6dace80654964cc4ca7d2db8092
Author: Lin Ming <ming.m.lin@xxxxxxxxx>
AuthorDate: Fri, 23 Apr 2010 13:56:33 +0800
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 18 May 2010 18:59:12 +0200

perf, sparc: Implement group scheduling transactional APIs

Convert to the transactional PMU API and remove the duplication of
group_sched_in().

[cross build only]

Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
Acked-by: David Miller <davem@xxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <1272002193.5707.65.camel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/sparc/kernel/perf_event.c | 108 ++++++++++++++++++++++-----------------
1 files changed, 61 insertions(+), 47 deletions(-)

diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index e277193..cf4ce26 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -91,6 +91,8 @@ struct cpu_hw_events {

/* Enabled/disable state. */
int enabled;
+
+ unsigned int group_flag;
};
DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { .enabled = 1, };

@@ -980,53 +982,6 @@ static int collect_events(struct perf_event *group, int max_count,
return n;
}

-static void event_sched_in(struct perf_event *event)
-{
- event->state = PERF_EVENT_STATE_ACTIVE;
- event->oncpu = smp_processor_id();
- event->tstamp_running += event->ctx->time - event->tstamp_stopped;
- if (is_software_event(event))
- event->pmu->enable(event);
-}
-
-int hw_perf_group_sched_in(struct perf_event *group_leader,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
-{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
- struct perf_event *sub;
- int n0, n;
-
- if (!sparc_pmu)
- return 0;
-
- n0 = cpuc->n_events;
- n = collect_events(group_leader, perf_max_events - n0,
- &cpuc->event[n0], &cpuc->events[n0],
- &cpuc->current_idx[n0]);
- if (n < 0)
- return -EAGAIN;
- if (check_excludes(cpuc->event, n0, n))
- return -EINVAL;
- if (sparc_check_constraints(cpuc->event, cpuc->events, n + n0))
- return -EAGAIN;
- cpuc->n_events = n0 + n;
- cpuc->n_added += n;
-
- cpuctx->active_oncpu += n;
- n = 1;
- event_sched_in(group_leader);
- list_for_each_entry(sub, &group_leader->sibling_list, group_entry) {
- if (sub->state != PERF_EVENT_STATE_OFF) {
- event_sched_in(sub);
- n++;
- }
- }
- ctx->nr_active += n;
-
- return 1;
-}
-
static int sparc_pmu_enable(struct perf_event *event)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -1044,11 +999,20 @@ static int sparc_pmu_enable(struct perf_event *event)
cpuc->events[n0] = event->hw.event_base;
cpuc->current_idx[n0] = PIC_NO_INDEX;

+ /*
+ * If group events scheduling transaction was started,
+ * skip the schedulability test here, it will be peformed
+ * at commit time(->commit_txn) as a whole
+ */
+ if (cpuc->group_flag & PERF_EVENT_TXN_STARTED)
+ goto nocheck;
+
if (check_excludes(cpuc->event, n0, 1))
goto out;
if (sparc_check_constraints(cpuc->event, cpuc->events, n0 + 1))
goto out;

+nocheck:
cpuc->n_events++;
cpuc->n_added++;

@@ -1128,11 +1092,61 @@ static int __hw_perf_event_init(struct perf_event *event)
return 0;
}

+/*
+ * Start group events scheduling transaction
+ * Set the flag to make pmu::enable() not perform the
+ * schedulability test, it will be performed at commit time
+ */
+static void sparc_pmu_start_txn(const struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ cpuhw->group_flag |= PERF_EVENT_TXN_STARTED;
+}
+
+/*
+ * Stop group events scheduling transaction
+ * Clear the flag and pmu::enable() will perform the
+ * schedulability test.
+ */
+static void sparc_pmu_cancel_txn(const struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+
+ cpuhw->group_flag &= ~PERF_EVENT_TXN_STARTED;
+}
+
+/*
+ * Commit group events scheduling transaction
+ * Perform the group schedulability test as a whole
+ * Return 0 if success
+ */
+static int sparc_pmu_commit_txn(const struct pmu *pmu)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ int n;
+
+ if (!sparc_pmu)
+ return -EINVAL;
+
+ cpuc = &__get_cpu_var(cpu_hw_events);
+ n = cpuc->n_events;
+ if (check_excludes(cpuc->event, 0, n))
+ return -EINVAL;
+ if (sparc_check_constraints(cpuc->event, cpuc->events, n))
+ return -EAGAIN;
+
+ return 0;
+}
+
static const struct pmu pmu = {
.enable = sparc_pmu_enable,
.disable = sparc_pmu_disable,
.read = sparc_pmu_read,
.unthrottle = sparc_pmu_unthrottle,
+ .start_txn = sparc_pmu_start_txn,
+ .cancel_txn = sparc_pmu_cancel_txn,
+ .commit_txn = sparc_pmu_commit_txn,
};

const struct pmu *hw_perf_event_init(struct perf_event *event)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/