--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * event tracer
+ *
+ * Copyright (C) 2022 Google Inc, Steven Rostedt <rostedt@goodmis.org>
+ */
+
+#define pr_fmt(fmt) fmt
+
+#include <linux/trace_events.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <trace/events/sched.h>
+
+#define THIS_SYSTEM "custom_sched"
+
+#define SCHED_PRINT_FMT \
+ C("prev_prio=%d next_pid=%d next_prio=%d", REC->prev_prio, REC->next_pid, \
+ REC->next_prio)
+
+#define SCHED_WAKING_FMT \
+ C("pid=%d prio=%d", REC->pid, REC->prio)
+
+#undef C
+#define C(a, b...) a, b
+
+static struct trace_event_fields sched_switch_fields[] = {
+ {
+ .type = "unsigned short",
+ .name = "prev_prio",
+ .size = sizeof(short),
+ .align = __alignof__(short),
+ .is_signed = 0,
+ .filter_type = FILTER_OTHER,
+ },
+ {
+ .type = "unsigned short",
+ .name = "next_prio",
+ .size = sizeof(short),
+ .align = __alignof__(short),
+ .is_signed = 0,
+ .filter_type = FILTER_OTHER,
+ },
+ {
+ .type = "unsigned int",
+ .name = "next_prio",
+ .size = sizeof(int),
+ .align = __alignof__(int),
+ .is_signed = 0,
+ .filter_type = FILTER_OTHER,
+ },
+ {}
+};
+
+struct sched_event {
+ struct trace_entry ent;
+ unsigned short prev_prio;
+ unsigned short next_prio;
+ unsigned int next_pid;
+};
+
+static struct trace_event_fields sched_waking_fields[] = {
+ {
+ .type = "unsigned int",
+ .name = "pid",
+ .size = sizeof(int),
+ .align = __alignof__(int),
+ .is_signed = 0,
+ .filter_type = FILTER_OTHER,
+ },
+ {
+ .type = "unsigned short",
+ .name = "prio",
+ .size = sizeof(short),
+ .align = __alignof__(short),
+ .is_signed = 0,
+ .filter_type = FILTER_OTHER,
+ },
+ {}
+};
+
+struct wake_event {
+ struct trace_entry ent;
+ unsigned int pid;
+ unsigned short prio;
+};
+
+static void sched_switch_probe(void *data, bool preempt, struct task_struct *prev,
+ struct task_struct *next)
+{
+ struct trace_event_file *trace_file = data;
+ struct trace_event_buffer fbuffer;
+ struct sched_event *entry;
+
+ if (trace_trigger_soft_disabled(trace_file))
+ return;
+
+ entry = trace_event_buffer_reserve(&fbuffer, trace_file,
+ sizeof(*entry));
+
+ if (!entry)
+ return;
+
+ entry->prev_prio = prev->prio;
+ entry->next_prio = next->prio;
+ entry->next_pid = next->pid;
+
+ trace_event_buffer_commit(&fbuffer);
+}
+
+static struct trace_event_class sched_switch_class = {
+ .system = THIS_SYSTEM,
+ .reg = trace_event_reg,
+ .fields_array = sched_switch_fields,
+ .fields = LIST_HEAD_INIT(sched_switch_class.fields),
+ .probe = sched_switch_probe,
+};
+
+static void sched_waking_probe(void *data, struct task_struct *t)
+{
+ struct trace_event_file *trace_file = data;
+ struct trace_event_buffer fbuffer;
+ struct wake_event *entry;
+
+ if (trace_trigger_soft_disabled(trace_file))
+ return;
+
+ entry = trace_event_buffer_reserve(&fbuffer, trace_file,
+ sizeof(*entry));
+
+ if (!entry)
+ return;
+
+ entry->prio = t->prio;
+ entry->pid = t->pid;
+
+ trace_event_buffer_commit(&fbuffer);
+}
+
+static struct trace_event_class sched_waking_class = {
+ .system = THIS_SYSTEM,
+ .reg = trace_event_reg,
+ .fields_array = sched_waking_fields,
+ .fields = LIST_HEAD_INIT(sched_waking_class.fields),
+ .probe = sched_waking_probe,
+};
+
+static enum print_line_t sched_switch_output(struct trace_iterator *iter, int flags,
+ struct trace_event *trace_event)
+{
+ struct trace_seq *s = &iter->seq;
+ struct sched_event *REC = (struct sched_event *)iter->ent;
+ int ret;
+
+ ret = trace_raw_output_prep(iter, trace_event);
+ if (ret != TRACE_TYPE_HANDLED)
+ return ret;
+
+ trace_seq_printf(s, SCHED_PRINT_FMT);
+ trace_seq_putc(s, '\n');
+
+ return trace_handle_return(s);
+}
+
+static struct trace_event_functions sched_switch_funcs = {
+ .trace = sched_switch_output,
+};
+
+static enum print_line_t sched_waking_output(struct trace_iterator *iter, int flags,
+ struct trace_event *trace_event)
+{
+ struct trace_seq *s = &iter->seq;
+ struct wake_event *REC = (struct wake_event *)iter->ent;
+ int ret;
+
+ ret = trace_raw_output_prep(iter, trace_event);
+ if (ret != TRACE_TYPE_HANDLED)
+ return ret;
+
+ trace_seq_printf(s, SCHED_WAKING_FMT);
+ trace_seq_putc(s, '\n');
+
+ return trace_handle_return(s);
+}
+
+static struct trace_event_functions sched_waking_funcs = {
+ .trace = sched_waking_output,
+};
+
+#undef C
+#define C(a, b...) #a "," __stringify(b)
+
+static struct trace_event_call sched_switch_call = {
+ .class = &sched_switch_class,
+ .event = {
+ .funcs = &sched_switch_funcs,
+ },
+ .print_fmt = SCHED_PRINT_FMT,
+ .module = THIS_MODULE,
+ .flags = TRACE_EVENT_FL_TRACEPOINT,
+};
+
+static struct trace_event_call sched_waking_call = {
+ .class = &sched_waking_class,
+ .event = {
+ .funcs = &sched_waking_funcs,
+ },
+ .print_fmt = SCHED_WAKING_FMT,
+ .module = THIS_MODULE,
+ .flags = TRACE_EVENT_FL_TRACEPOINT,
+};
+
+static void fct(struct tracepoint *tp, void *priv)
+{
+ if (tp->name && strcmp(tp->name, "sched_switch") == 0)
+ sched_switch_call.tp = tp;
+ else if (tp->name && strcmp(tp->name, "sched_waking") == 0)
+ sched_waking_call.tp = tp;
+}
+
+static int add_event(struct trace_event_call *call)
+{
+ int ret;
+
+ ret = register_trace_event(&call->event);
+ if (WARN_ON(!ret))
+ return -ENODEV;
+
+ ret = trace_add_event_call(call);
+ if (WARN_ON(ret))
+ unregister_trace_event(&call->event);
+
+ return ret;
+}
+
+static int __init trace_sched_init(void)
+{
+ int ret;
+
+ check_trace_callback_type_sched_switch(sched_switch_probe);
+ check_trace_callback_type_sched_waking(sched_waking_probe);
+
+ for_each_kernel_tracepoint(fct, NULL);
+
+ ret = add_event(&sched_switch_call);
+ if (ret)
+ return ret;
+
+ ret = add_event(&sched_waking_call);
+ if (ret)
+ trace_remove_event_call(&sched_switch_call);
+
+ return ret;
+}
+
+static void __exit trace_sched_exit(void)
+{
+ trace_set_clr_event(THIS_SYSTEM, "sched_switch", 0);
+ trace_set_clr_event(THIS_SYSTEM, "sched_waking", 0);
+
+ trace_remove_event_call(&sched_switch_call);
+ trace_remove_event_call(&sched_waking_call);
+}
+
+module_init(trace_sched_init);
+module_exit(trace_sched_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("Custom scheduling events");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff