[RFC PATCH 1/5] trace: Add trace_ipi_send_{cpu, cpumask}

[Valentin Schneider]

trace_ipi_raise is unsuitable for generically tracing IPI sources; add a
variant of it that takes a callsite and a CPU. Define a macro helper for
handling IPIs sent to multiple CPUs.

Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
---
 include/trace/events/ipi.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/include/trace/events/ipi.h b/include/trace/events/ipi.h
index 0be71dad6ec0..fd2f2aeb36fe 100644
--- a/include/trace/events/ipi.h
+++ b/include/trace/events/ipi.h
@@ -35,6 +35,33 @@ TRACE_EVENT(ipi_raise,
 	TP_printk("target_mask=%s (%s)", __get_bitmask(target_cpus), __entry->reason)
 );
 
+TRACE_EVENT(ipi_send_cpu,
+
+	TP_PROTO(unsigned long callsite, unsigned int cpu),
+
+	TP_ARGS(callsite, cpu),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, callsite)
+		__field(unsigned int, cpu)
+	),
+
+	TP_fast_assign(
+		__entry->callsite = callsite;
+		__entry->cpu      = cpu;
+	),
+
+	TP_printk("callsite=%pS target_cpu=%d", (void *)__entry->callsite, __entry->cpu)
+);
+
+#define trace_ipi_send_cpumask(callsite, mask) do {		\
+	if (static_key_false(&__tracepoint_ipi_send_cpu.key)) { \
+		int cpu;					\
+		for_each_cpu(cpu, mask)				\
+			trace_ipi_send_cpu(callsite, cpu);	\
+	}							\
+} while (0)
+
 DECLARE_EVENT_CLASS(ipi_handler,
 
 	TP_PROTO(const char *reason),
-- 
2.31.1