[RFC][PATCH 09/11] perf: Default PMU ops

Peter Zijlstra
2010-06-24T14:38:52Z

[-- Attachment #1: perf-default-ops.patch --]
[-- Type: text/plain, Size: 2292 bytes --]

Provide default implementations for the pmu txn methods, this allows
us to remove some conditional code.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/perf_event.c | 48 ++++++++++++++++++++++++++++++++++++------------
1 file changed, 36 insertions(+), 12 deletions(-)

Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -656,21 +656,14 @@ group_sched_in(struct perf_event *group_
{
struct perf_event *event, *partial_group = NULL;
struct pmu *pmu = group_event->pmu;
- bool txn = false;

if (group_event->state == PERF_EVENT_STATE_OFF)
return 0;

- /* Check if group transaction availabe */
- if (pmu->start_txn)
- txn = true;
-
- if (txn)
- pmu->start_txn(pmu);
+ pmu->start_txn(pmu);

if (event_sched_in(group_event, cpuctx, ctx)) {
- if (txn)
- pmu->cancel_txn(pmu);
+ pmu->cancel_txn(pmu);
return -EAGAIN;
}

@@ -684,7 +677,7 @@ group_sched_in(struct perf_event *group_
}
}

- if (!txn || !pmu->commit_txn(pmu))
+ if (!pmu->commit_txn(pmu))
return 0;

group_error:
@@ -699,8 +692,7 @@ group_error:
}
event_sched_out(group_event, cpuctx, ctx);

- if (txn)
- pmu->cancel_txn(pmu);
+ pmu->cancel_txn(pmu);

return -EAGAIN;
}
@@ -4755,6 +4747,26 @@ static struct list_head pmus;
static DEFINE_MUTEX(pmus_lock);
static struct srcu_struct pmus_srcu;

+static void perf_pmu_nop(struct pmu *pmu)
+{
+}
+
+static void perf_pmu_start_txn(struct pmu *pmu)
+{
+ perf_pmu_disable(pmu);
+}
+
+static int perf_pmu_commit_txn(struct pmu *pmu)
+{
+ perf_pmu_enable(pmu);
+ return 0;
+}
+
+static void perf_pmu_cancel_txn(struct pmu *pmu)
+{
+ perf_pmu_enable(pmu);
+}
+
int perf_pmu_register(struct pmu *pmu)
{
int ret;
@@ -4764,6 +4776,18 @@ int perf_pmu_register(struct pmu *pmu)
pmu->pmu_disable_count = alloc_percpu(int);
if (!pmu->pmu_disable_count)
goto unlock;
+
+ if (!pmu->pmu_enable) {
+ pmu->pmu_enable = perf_pmu_nop;
+ pmu->pmu_disable = perf_pmu_nop;
+ }
+
+ if (!pmu->start_txn) {
+ pmu->start_txn = perf_pmu_start_txn;
+ pmu->commit_txn = perf_pmu_commit_txn;
+ pmu->cancel_txn = perf_pmu_cancel_txn;
+ }
+
list_add_rcu(&pmu->entry, &pmus);
ret = 0;