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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-05-19 14:02:22 +0200
committerIngo Molnar <mingo@elte.hu>2010-05-21 11:37:56 +0200
commit1c024eca51fdc965290acf342ae16a476c2189d0 (patch)
tree28dc160cc70a20eeb8b8825d6d52ea88a6188413 /kernel/perf_event.c
parentb7e2ecef92d2e7785e6d76b41e5ba8bcbc45259d (diff)
downloadlinux-1c024eca51fdc965290acf342ae16a476c2189d0.tar.bz2
perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events
Avoid the swevent hash-table by using per-tracepoint hlists. Also, avoid conditionals on the fast path by ordering with probe unregister so that we should never get on the callback path without the data being there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100521090710.473188012@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r--kernel/perf_event.c94
1 files changed, 48 insertions, 46 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 45b7aec55458..3f2cc313ee25 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4005,9 +4005,6 @@ static void perf_swevent_add(struct perf_event *event, u64 nr,
perf_swevent_overflow(event, 0, nmi, data, regs);
}
-static int perf_tp_event_match(struct perf_event *event,
- struct perf_sample_data *data);
-
static int perf_exclude_event(struct perf_event *event,
struct pt_regs *regs)
{
@@ -4037,10 +4034,6 @@ static int perf_swevent_match(struct perf_event *event,
if (perf_exclude_event(event, regs))
return 0;
- if (event->attr.type == PERF_TYPE_TRACEPOINT &&
- !perf_tp_event_match(event, data))
- return 0;
-
return 1;
}
@@ -4122,7 +4115,7 @@ end:
int perf_swevent_get_recursion_context(void)
{
- struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
int rctx;
if (in_nmi())
@@ -4134,10 +4127,8 @@ int perf_swevent_get_recursion_context(void)
else
rctx = 0;
- if (cpuctx->recursion[rctx]) {
- put_cpu_var(perf_cpu_context);
+ if (cpuctx->recursion[rctx])
return -1;
- }
cpuctx->recursion[rctx]++;
barrier();
@@ -4151,7 +4142,6 @@ void perf_swevent_put_recursion_context(int rctx)
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
barrier();
cpuctx->recursion[rctx]--;
- put_cpu_var(perf_cpu_context);
}
EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context);
@@ -4162,6 +4152,7 @@ void __perf_sw_event(u32 event_id, u64 nr, int nmi,
struct perf_sample_data data;
int rctx;
+ preempt_disable_notrace();
rctx = perf_swevent_get_recursion_context();
if (rctx < 0)
return;
@@ -4171,6 +4162,7 @@ void __perf_sw_event(u32 event_id, u64 nr, int nmi,
do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs);
perf_swevent_put_recursion_context(rctx);
+ preempt_enable_notrace();
}
static void perf_swevent_read(struct perf_event *event)
@@ -4486,11 +4478,43 @@ static int swevent_hlist_get(struct perf_event *event)
#ifdef CONFIG_EVENT_TRACING
-void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
- int entry_size, struct pt_regs *regs, void *event)
+static const struct pmu perf_ops_tracepoint = {
+ .enable = perf_trace_enable,
+ .disable = perf_trace_disable,
+ .read = perf_swevent_read,
+ .unthrottle = perf_swevent_unthrottle,
+};
+
+static int perf_tp_filter_match(struct perf_event *event,
+ struct perf_sample_data *data)
+{
+ void *record = data->raw->data;
+
+ if (likely(!event->filter) || filter_match_preds(event->filter, record))
+ return 1;
+ return 0;
+}
+
+static int perf_tp_event_match(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ if (perf_exclude_event(event, regs))
+ return 0;
+
+ if (!perf_tp_filter_match(event, data))
+ return 0;
+
+ return 1;
+}
+
+void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
+ struct pt_regs *regs, struct hlist_head *head)
{
- const int type = PERF_TYPE_TRACEPOINT;
struct perf_sample_data data;
+ struct perf_event *event;
+ struct hlist_node *node;
+
struct perf_raw_record raw = {
.size = entry_size,
.data = record,
@@ -4499,30 +4523,18 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
perf_sample_data_init(&data, addr);
data.raw = &raw;
- if (!event) {
- do_perf_sw_event(type, event_id, count, 1, &data, regs);
- return;
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
+ if (perf_tp_event_match(event, &data, regs))
+ perf_swevent_add(event, count, 1, &data, regs);
}
-
- if (perf_swevent_match(event, type, event_id, &data, regs))
- perf_swevent_add(event, count, 1, &data, regs);
+ rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(perf_tp_event);
-static int perf_tp_event_match(struct perf_event *event,
- struct perf_sample_data *data)
-{
- void *record = data->raw->data;
-
- if (likely(!event->filter) || filter_match_preds(event->filter, record))
- return 1;
- return 0;
-}
-
static void tp_perf_event_destroy(struct perf_event *event)
{
- perf_trace_disable(event->attr.config);
- swevent_hlist_put(event);
+ perf_trace_destroy(event);
}
static const struct pmu *tp_perf_event_init(struct perf_event *event)
@@ -4538,17 +4550,13 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event)
!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
- if (perf_trace_enable(event->attr.config, event))
+ err = perf_trace_init(event);
+ if (err)
return NULL;
event->destroy = tp_perf_event_destroy;
- err = swevent_hlist_get(event);
- if (err) {
- perf_trace_disable(event->attr.config);
- return ERR_PTR(err);
- }
- return &perf_ops_generic;
+ return &perf_ops_tracepoint;
}
static int perf_event_set_filter(struct perf_event *event, void __user *arg)
@@ -4576,12 +4584,6 @@ static void perf_event_free_filter(struct perf_event *event)
#else
-static int perf_tp_event_match(struct perf_event *event,
- struct perf_sample_data *data)
-{
- return 1;
-}
-
static const struct pmu *tp_perf_event_init(struct perf_event *event)
{
return NULL;