perf: Remove the nmi parameter from the swevent and overflow interface
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 270e32f..dbd1ca7 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3972,7 +3972,7 @@
}
}
-static void perf_event_output(struct perf_event *event, int nmi,
+static void perf_event_output(struct perf_event *event,
struct perf_sample_data *data,
struct pt_regs *regs)
{
@@ -3984,7 +3984,7 @@
perf_prepare_sample(&header, data, event, regs);
- if (perf_output_begin(&handle, event, header.size, nmi, 1))
+ if (perf_output_begin(&handle, event, header.size, 1))
goto exit;
perf_output_sample(&handle, &header, data, event);
@@ -4024,7 +4024,7 @@
int ret;
perf_event_header__init_id(&read_event.header, &sample, event);
- ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0);
+ ret = perf_output_begin(&handle, event, read_event.header.size, 0);
if (ret)
return;
@@ -4067,7 +4067,7 @@
perf_event_header__init_id(&task_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, event,
- task_event->event_id.header.size, 0, 0);
+ task_event->event_id.header.size, 0);
if (ret)
goto out;
@@ -4204,7 +4204,7 @@
perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, event,
- comm_event->event_id.header.size, 0, 0);
+ comm_event->event_id.header.size, 0);
if (ret)
goto out;
@@ -4351,7 +4351,7 @@
perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, event,
- mmap_event->event_id.header.size, 0, 0);
+ mmap_event->event_id.header.size, 0);
if (ret)
goto out;
@@ -4546,7 +4546,7 @@
perf_event_header__init_id(&throttle_event.header, &sample, event);
ret = perf_output_begin(&handle, event,
- throttle_event.header.size, 1, 0);
+ throttle_event.header.size, 0);
if (ret)
return;
@@ -4559,7 +4559,7 @@
* Generic event overflow handling, sampling.
*/
-static int __perf_event_overflow(struct perf_event *event, int nmi,
+static int __perf_event_overflow(struct perf_event *event,
int throttle, struct perf_sample_data *data,
struct pt_regs *regs)
{
@@ -4602,34 +4602,28 @@
if (events && atomic_dec_and_test(&event->event_limit)) {
ret = 1;
event->pending_kill = POLL_HUP;
- if (nmi) {
- event->pending_disable = 1;
- irq_work_queue(&event->pending);
- } else
- perf_event_disable(event);
+ event->pending_disable = 1;
+ irq_work_queue(&event->pending);
}
if (event->overflow_handler)
- event->overflow_handler(event, nmi, data, regs);
+ event->overflow_handler(event, data, regs);
else
- perf_event_output(event, nmi, data, regs);
+ perf_event_output(event, data, regs);
if (event->fasync && event->pending_kill) {
- if (nmi) {
- event->pending_wakeup = 1;
- irq_work_queue(&event->pending);
- } else
- perf_event_wakeup(event);
+ event->pending_wakeup = 1;
+ irq_work_queue(&event->pending);
}
return ret;
}
-int perf_event_overflow(struct perf_event *event, int nmi,
+int perf_event_overflow(struct perf_event *event,
struct perf_sample_data *data,
struct pt_regs *regs)
{
- return __perf_event_overflow(event, nmi, 1, data, regs);
+ return __perf_event_overflow(event, 1, data, regs);
}
/*
@@ -4678,7 +4672,7 @@
}
static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
- int nmi, struct perf_sample_data *data,
+ struct perf_sample_data *data,
struct pt_regs *regs)
{
struct hw_perf_event *hwc = &event->hw;
@@ -4692,7 +4686,7 @@
return;
for (; overflow; overflow--) {
- if (__perf_event_overflow(event, nmi, throttle,
+ if (__perf_event_overflow(event, throttle,
data, regs)) {
/*
* We inhibit the overflow from happening when
@@ -4705,7 +4699,7 @@
}
static void perf_swevent_event(struct perf_event *event, u64 nr,
- int nmi, struct perf_sample_data *data,
+ struct perf_sample_data *data,
struct pt_regs *regs)
{
struct hw_perf_event *hwc = &event->hw;
@@ -4719,12 +4713,12 @@
return;
if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
- return perf_swevent_overflow(event, 1, nmi, data, regs);
+ return perf_swevent_overflow(event, 1, data, regs);
if (local64_add_negative(nr, &hwc->period_left))
return;
- perf_swevent_overflow(event, 0, nmi, data, regs);
+ perf_swevent_overflow(event, 0, data, regs);
}
static int perf_exclude_event(struct perf_event *event,
@@ -4812,7 +4806,7 @@
}
static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
- u64 nr, int nmi,
+ u64 nr,
struct perf_sample_data *data,
struct pt_regs *regs)
{
@@ -4828,7 +4822,7 @@
hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
if (perf_swevent_match(event, type, event_id, data, regs))
- perf_swevent_event(event, nr, nmi, data, regs);
+ perf_swevent_event(event, nr, data, regs);
}
end:
rcu_read_unlock();
@@ -4849,8 +4843,7 @@
put_recursion_context(swhash->recursion, rctx);
}
-void __perf_sw_event(u32 event_id, u64 nr, int nmi,
- struct pt_regs *regs, u64 addr)
+void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
struct perf_sample_data data;
int rctx;
@@ -4862,7 +4855,7 @@
perf_sample_data_init(&data, addr);
- do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs);
+ do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
perf_swevent_put_recursion_context(rctx);
preempt_enable_notrace();
@@ -5110,7 +5103,7 @@
hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
if (perf_tp_event_match(event, &data, regs))
- perf_swevent_event(event, count, 1, &data, regs);
+ perf_swevent_event(event, count, &data, regs);
}
perf_swevent_put_recursion_context(rctx);
@@ -5203,7 +5196,7 @@
perf_sample_data_init(&sample, bp->attr.bp_addr);
if (!bp->hw.state && !perf_exclude_event(bp, regs))
- perf_swevent_event(bp, 1, 1, &sample, regs);
+ perf_swevent_event(bp, 1, &sample, regs);
}
#endif
@@ -5232,7 +5225,7 @@
if (regs && !perf_exclude_event(event, regs)) {
if (!(event->attr.exclude_idle && current->pid == 0))
- if (perf_event_overflow(event, 0, &data, regs))
+ if (perf_event_overflow(event, &data, regs))
ret = HRTIMER_NORESTART;
}