[patch V3 21/44] x86/tracing: Build tracepoints only when they are used

From: Thomas Gleixner
Date: Mon Aug 28 2017 - 02:59:46 EST


The tracepoint macro magic emits code for all tracepoints in a event header
file. That code stays around even if the tracepoint is not used at all. The
linker does not discard it.

Build the various irq_vector tracepoints dependent on the appropriate CONFIG
switches.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/include/asm/trace/irq_vectors.h | 36 ++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 12 deletions(-)

--- a/arch/x86/include/asm/trace/irq_vectors.h
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -7,6 +7,8 @@
#include <linux/tracepoint.h>
#include <asm/trace/common.h>

+#ifdef CONFIG_X86_LOCAL_APIC
+
extern int trace_resched_ipi_reg(void);
extern void trace_resched_ipi_unreg(void);

@@ -53,18 +55,6 @@ DEFINE_EVENT_FN(x86_irq_vector, name##_e
DEFINE_IRQ_VECTOR_EVENT(local_timer);

/*
- * The ifdef is required because that tracepoint macro hell emits tracepoint
- * code in files which include this header even if the tracepoint is not
- * enabled. Brilliant stuff that.
- */
-#ifdef CONFIG_SMP
-/*
- * reschedule - called when entering/exiting a reschedule vector handler
- */
-DEFINE_RESCHED_IPI_EVENT(reschedule);
-#endif
-
-/*
* spurious_apic - called when entering/exiting a spurious apic vector handler
*/
DEFINE_IRQ_VECTOR_EVENT(spurious_apic);
@@ -80,6 +70,7 @@ DEFINE_IRQ_VECTOR_EVENT(error_apic);
*/
DEFINE_IRQ_VECTOR_EVENT(x86_platform_ipi);

+#ifdef CONFIG_IRQ_WORK
/*
* irq_work - called when entering/exiting a irq work interrupt
* vector handler
@@ -96,6 +87,18 @@ DEFINE_IRQ_VECTOR_EVENT(irq_work);
* 4) goto 1
*/
TRACE_EVENT_PERF_PERM(irq_work_exit, is_sampling_event(p_event) ? -EPERM : 0);
+#endif
+
+/*
+ * The ifdef is required because that tracepoint macro hell emits tracepoint
+ * code in files which include this header even if the tracepoint is not
+ * enabled. Brilliant stuff that.
+ */
+#ifdef CONFIG_SMP
+/*
+ * reschedule - called when entering/exiting a reschedule vector handler
+ */
+DEFINE_RESCHED_IPI_EVENT(reschedule);

/*
* call_function - called when entering/exiting a call function interrupt
@@ -108,24 +111,33 @@ DEFINE_IRQ_VECTOR_EVENT(call_function);
* single interrupt vector handler
*/
DEFINE_IRQ_VECTOR_EVENT(call_function_single);
+#endif

+#ifdef CONFIG_X86_MCE_THRESHOLD
/*
* threshold_apic - called when entering/exiting a threshold apic interrupt
* vector handler
*/
DEFINE_IRQ_VECTOR_EVENT(threshold_apic);
+#endif

+#ifdef CONFIG_X86_MCE_AMD
/*
* deferred_error_apic - called when entering/exiting a deferred apic interrupt
* vector handler
*/
DEFINE_IRQ_VECTOR_EVENT(deferred_error_apic);
+#endif

+#ifdef CONFIG_X86_THERMAL_VECTOR
/*
* thermal_apic - called when entering/exiting a thermal apic interrupt
* vector handler
*/
DEFINE_IRQ_VECTOR_EVENT(thermal_apic);
+#endif
+
+#endif /* CONFIG_X86_LOCAL_APIC */

#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH .