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path: root/samples/trace_events/trace_custom_sched.c
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Diffstat (limited to 'samples/trace_events/trace_custom_sched.c')
-rw-r--r--samples/trace_events/trace_custom_sched.c259
1 files changed, 24 insertions, 235 deletions
diff --git a/samples/trace_events/trace_custom_sched.c b/samples/trace_events/trace_custom_sched.c
index 70a12c32ff99..b99d9ab7db85 100644
--- a/samples/trace_events/trace_custom_sched.c
+++ b/samples/trace_events/trace_custom_sched.c
@@ -11,256 +11,45 @@
#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)
+/*
+ * Must include the event header that the custom event will attach to,
+ * from the C file, and not in the custom header file.
+ */
+#include <trace/events/sched.h>
-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,
-};
+/* Declare CREATE_CUSTOM_TRACE_EVENTS before including custom header */
+#define CREATE_CUSTOM_TRACE_EVENTS
-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,
-};
+#include "trace_custom_sched.h"
+/*
+ * As the trace events are not exported to modules, the use of
+ * for_each_kernel_tracepoint() is needed to find the trace event
+ * to attach to. The fct() function below, is a callback that
+ * will be called for every event.
+ *
+ * Helper functions are created by the TRACE_CUSTOM_EVENT() macro
+ * update the event. Those are of the form:
+ *
+ * trace_custom_event_<event>_update()
+ *
+ * Where <event> is the event to attach.
+ */
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;
+ trace_custom_event_sched_switch_update(tp);
+ trace_custom_event_sched_waking_update(tp);
}
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;
+ return 0;
}
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);