Mika/clocksource_switch_benchmark
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Add patches/tracepoint_integration.patch

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Mika 2025-12-03 13:44:59 +00:00
commit 43781a20da
1 changed files with 118 additions and 0 deletions
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118
patches/tracepoint_integration.patch Normal file
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@ -0,0 +1,118 @@
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e1f8f7b06e3d..f3a7b4a6c2dd 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -23,6 +23,7 @@
#include <linux/moduleparam.h>
#include <linux/hardirq.h>
#include <linux/clocksource.h>
+#include <linux/ktime.h>
#include <linux/workqueue.h>
#include <linux/suspend.h>
#include <linux/mutex.h>
@@ -38,6 +39,7 @@
#include <trace/events/timer.h>
#include <trace/events/sched.h>
#include <trace/events/clocksource.h>
+#include <trace/events/clocksource_switch.h>
static DEFINE_SPINLOCK(clocksource_lock);
@@ -246,6 +248,11 @@ void do_clocksource_switch(struct clocksource *cs)
struct clocksource *old_clock;
unsigned long flags;
struct clocksource *old = curr_clocksource;
+ struct trace_point_data tp_data = {
+ .timestamp_switch = ktime_get_ns(),
+ .timestamp_baseline_recalc = 0,
+ .timestamp_read = 0,
+ };
if (!cs)
return;
@@ -320,6 +327,7 @@ void do_clocksource_switch(struct clocksource *cs)
clocksource_stop_watchdog(old);
clocksource_watchdog_lock(flags);
+
__clocksource_change_rating(cs, RATING_INTERNAL);
clocksource_select();
@@ -343,6 +351,8 @@ void do_clocksource_switch(struct clocksource *cs)
cs->flags &= ~CLOCK_SOURCE_SUSPENDED;
cs->enable(cs);
+ tp_data.timestamp_baseline_recalc = ktime_get_ns();
+
clocksource_start_watchdog(cs);
if (old)
@@ -352,11 +362,22 @@ void do_clocksource_switch(struct clocksource *cs)
write_seqcount_begin(&clock->seq);
clock->clocksource = cs;
clock->cycle_last = curr_clocksource->read(curr_clocksource);
+ tp_data.timestamp_read = ktime_get_ns();
clock->mask = curr_clocksource->mask;
clock->mult = curr_clocksource->mult;
clock->shift = curr_clocksource->shift;
write_seqcount_end(&clock->seq);
raw_spin_unlock_irqrestore(&clock->lock, flags);
+
+ if (!tp_data.timestamp_baseline_recalc)
+ tp_data.timestamp_baseline_recalc = tp_data.timestamp_switch;
+
+ if (!tp_data.timestamp_read)
+ tp_data.timestamp_read = tp_data.timestamp_baseline_recalc;
+
+ trace_clocksource_switch_latency(&tp_data);
}
diff --git a/include/trace/events/clocksource_switch.h b/include/trace/events/clocksource_switch.h
new file mode 100644
index 000000000000..5e4c1a1d3c31
--- /dev/null
+++ b/include/trace/events/clocksource_switch.h
@@ -0,0 +1,53 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM clocksource_switch
+
+#if !defined(_TRACE_CLOCKSOURCE_SWITCH_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_CLOCKSOURCE_SWITCH_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+struct trace_point_data {
+ u64 timestamp_switch;
+ u64 timestamp_baseline_recalc;
+ u64 timestamp_read;
+};
+
+TRACE_EVENT(clocksource_switch_latency,
+ TP_PROTO(const struct trace_point_data *tp),
+ TP_ARGS(tp),
+ TP_STRUCT__entry(
+ __field(u64, timestamp_switch)
+ __field(u64, timestamp_baseline_recalc)
+ __field(u64, timestamp_read)
+ ),
+ TP_fast_assign(
+ __entry->timestamp_switch = tp->timestamp_switch;
+ __entry->timestamp_baseline_recalc = tp->timestamp_baseline_recalc;
+ __entry->timestamp_read = tp->timestamp_read;
+ ),
+ TP_printk("switch=%llu ns baseline=%llu ns read=%llu ns",
+ __entry->timestamp_switch,
+ __entry->timestamp_baseline_recalc,
+ __entry->timestamp_read)
+);
+
+#endif /* _TRACE_CLOCKSOURCE_SWITCH_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH trace/events
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE clocksource_switch
+
+#include <trace/define_trace.h>