summaryrefslogtreecommitdiff
path: root/kernel/events/core.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r--kernel/events/core.c109
1 files changed, 105 insertions, 4 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a1339b1..e818389 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -163,6 +163,7 @@ static atomic_t nr_mmap_events __read_mostly;
static atomic_t nr_comm_events __read_mostly;
static atomic_t nr_task_events __read_mostly;
static atomic_t nr_freq_events __read_mostly;
+static atomic_t nr_switch_events __read_mostly;
static LIST_HEAD(pmus);
static DEFINE_MUTEX(pmus_lock);
@@ -2619,6 +2620,9 @@ static void perf_pmu_sched_task(struct task_struct *prev,
local_irq_restore(flags);
}
+static void perf_event_switch(struct task_struct *task,
+ struct task_struct *next_prev, bool sched_in);
+
#define for_each_task_context_nr(ctxn) \
for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
@@ -2641,6 +2645,9 @@ void __perf_event_task_sched_out(struct task_struct *task,
if (__this_cpu_read(perf_sched_cb_usages))
perf_pmu_sched_task(task, next, false);
+ if (atomic_read(&nr_switch_events))
+ perf_event_switch(task, next, false);
+
for_each_task_context_nr(ctxn)
perf_event_context_sched_out(task, ctxn, next);
@@ -2831,6 +2838,9 @@ void __perf_event_task_sched_in(struct task_struct *prev,
if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
perf_cgroup_sched_in(prev, task);
+ if (atomic_read(&nr_switch_events))
+ perf_event_switch(task, prev, true);
+
if (__this_cpu_read(perf_sched_cb_usages))
perf_pmu_sched_task(prev, task, true);
}
@@ -3507,6 +3517,10 @@ static void unaccount_event(struct perf_event *event)
atomic_dec(&nr_task_events);
if (event->attr.freq)
atomic_dec(&nr_freq_events);
+ if (event->attr.context_switch) {
+ static_key_slow_dec_deferred(&perf_sched_events);
+ atomic_dec(&nr_switch_events);
+ }
if (is_cgroup_event(event))
static_key_slow_dec_deferred(&perf_sched_events);
if (has_branch_stack(event))
@@ -6078,6 +6092,91 @@ void perf_log_lost_samples(struct perf_event *event, u64 lost)
}
/*
+ * context_switch tracking
+ */
+
+struct perf_switch_event {
+ struct task_struct *task;
+ struct task_struct *next_prev;
+
+ struct {
+ struct perf_event_header header;
+ u32 next_prev_pid;
+ u32 next_prev_tid;
+ } event_id;
+};
+
+static int perf_event_switch_match(struct perf_event *event)
+{
+ return event->attr.context_switch;
+}
+
+static void perf_event_switch_output(struct perf_event *event, void *data)
+{
+ struct perf_switch_event *se = data;
+ struct perf_output_handle handle;
+ struct perf_sample_data sample;
+ int ret;
+
+ if (!perf_event_switch_match(event))
+ return;
+
+ /* Only CPU-wide events are allowed to see next/prev pid/tid */
+ if (event->ctx->task) {
+ se->event_id.header.type = PERF_RECORD_SWITCH;
+ se->event_id.header.size = sizeof(se->event_id.header);
+ } else {
+ se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
+ se->event_id.header.size = sizeof(se->event_id);
+ se->event_id.next_prev_pid =
+ perf_event_pid(event, se->next_prev);
+ se->event_id.next_prev_tid =
+ perf_event_tid(event, se->next_prev);
+ }
+
+ perf_event_header__init_id(&se->event_id.header, &sample, event);
+
+ ret = perf_output_begin(&handle, event, se->event_id.header.size);
+ if (ret)
+ return;
+
+ if (event->ctx->task)
+ perf_output_put(&handle, se->event_id.header);
+ else
+ perf_output_put(&handle, se->event_id);
+
+ perf_event__output_id_sample(event, &handle, &sample);
+
+ perf_output_end(&handle);
+}
+
+static void perf_event_switch(struct task_struct *task,
+ struct task_struct *next_prev, bool sched_in)
+{
+ struct perf_switch_event switch_event;
+
+ /* N.B. caller checks nr_switch_events != 0 */
+
+ switch_event = (struct perf_switch_event){
+ .task = task,
+ .next_prev = next_prev,
+ .event_id = {
+ .header = {
+ /* .type */
+ .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
+ /* .size */
+ },
+ /* .next_prev_pid */
+ /* .next_prev_tid */
+ },
+ };
+
+ perf_event_aux(perf_event_switch_output,
+ &switch_event,
+ NULL);
+}
+
+/*
* IRQ throttle logging
*/
@@ -6136,8 +6235,6 @@ static void perf_log_itrace_start(struct perf_event *event)
event->hw.itrace_started)
return;
- event->hw.itrace_started = 1;
-
rec.header.type = PERF_RECORD_ITRACE_START;
rec.header.misc = 0;
rec.header.size = sizeof(rec);
@@ -6845,8 +6942,8 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
if (event->tp_event->prog)
return -EEXIST;
- if (!(event->tp_event->flags & TRACE_EVENT_FL_KPROBE))
- /* bpf programs can only be attached to kprobes */
+ if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE))
+ /* bpf programs can only be attached to u/kprobes */
return -EINVAL;
prog = bpf_prog_get(prog_fd);
@@ -7575,6 +7672,10 @@ static void account_event(struct perf_event *event)
if (atomic_inc_return(&nr_freq_events) == 1)
tick_nohz_full_kick_all();
}
+ if (event->attr.context_switch) {
+ atomic_inc(&nr_switch_events);
+ static_key_slow_inc(&perf_sched_events.key);
+ }
if (has_branch_stack(event))
static_key_slow_inc(&perf_sched_events.key);
if (is_cgroup_event(event))