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perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events

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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>
This commit is contained in:
Peter Zijlstra
2010-05-19 14:02:22 +02:00
committed by Ingo Molnar
parent b7e2ecef92
commit 1c024eca51
7 changed files with 148 additions and 129 deletions
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102
kernel/perf_event.c
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@ -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)
@ -4486,30 +4478,14 @@ 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)
{
const int type = PERF_TYPE_TRACEPOINT;
struct perf_sample_data data;
struct perf_raw_record raw = {
.size = entry_size,
.data = record,
};
static const struct pmu perf_ops_tracepoint = {
.enable = perf_trace_enable,
.disable = perf_trace_disable,
.read = perf_swevent_read,
.unthrottle = perf_swevent_unthrottle,
};
perf_sample_data_init(&data, addr);
data.raw = &raw;
if (!event) {
do_perf_sw_event(type, event_id, count, 1, &data, regs);
return;
}
if (perf_swevent_match(event, type, event_id, &data, regs))
perf_swevent_add(event, count, 1, &data, regs);
}
EXPORT_SYMBOL_GPL(perf_tp_event);
static int perf_tp_event_match(struct perf_event *event,
static int perf_tp_filter_match(struct perf_event *event,
struct perf_sample_data *data)
{
void *record = data->raw->data;
@ -4519,10 +4495,46 @@ static int perf_tp_event_match(struct perf_event *event,
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)
{
struct perf_sample_data data;
struct perf_event *event;
struct hlist_node *node;
struct perf_raw_record raw = {
.size = entry_size,
.data = record,
};
perf_sample_data_init(&data, addr);
data.raw = &raw;
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);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(perf_tp_event);
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;