Re: [PATCH v2 0/5] tracepoints: Add warnings for unused tracepoints and trace events

From: Steven Rostedt
Date: Fri Jun 13 2025 - 10:43:20 EST

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In reply to: Steven Rostedt: "Re: [PATCH v2 0/5] tracepoints: Add warnings for unused tracepoints and trace events"
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On Fri, 13 Jun 2025 10:28:34 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> And each DEFINE_EVENT() is approximately 1296 bytes.
> ((19559 - 2069) - 5819) / 9

Interesting enough, just raw tracepoints are not much better. I updated
the header file (attached) to have 10 of these, and compiled that.

DECLARE_TRACE(size_event_1,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

The result is:

text data bss dec hex filename
629 1440 0 2069 815 no-events.ko
44837 15424 0 60261 eb65 trace-events.ko
11495 8064 0 19559 4c67 define-events.ko
10865 4408 0 15273 3ba9 declare-trace.ko

Where each DECLARE_TRACE() ends up being 1320 bytes.
(15273 - 2069) / 10

This is slightly bigger than a DEFINE_EVENT(), but that's also because
the DEFINE_EVENT() shares some of the tracepoint creation in the
DECLARE_EVENT_CLASS(), where as that work is done fully in the
DECLARE_TRACE().

-- Steve

/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM event-sizes

#undef TRACE_SYSTEM_VAR
#define TRACE_SYSTEM_VAR event_sizes

#if !defined(_SIZE_EVENT_H) || defined(TRACE_HEADER_MULTI_READ)
#define _SIZE_EVENT_H

#include <linux/tracepoint.h>

#ifndef SIZE_EVENT_DEFINED
#define SIZE_EVENT_DEFINED
struct size_event_struct {
unsigned long a;
unsigned long b;
};
#endif

#define DEFINE_EVENT_SIZES 0
#define DEFINE_FULL_EVENTS 0
#define DEFINE_JUST_TRACEPOINTS 1

#if DEFINE_EVENT_SIZES

TRACE_EVENT(size_event_1,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);

#if DEFINE_FULL_EVENTS
TRACE_EVENT(size_event_2,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_3,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_4,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_5,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_6,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_7,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_8,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_9,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
TRACE_EVENT(size_event_10,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B),
TP_STRUCT__entry(
__field( unsigned long, Aa)
__field( unsigned long, Ab)
__field( unsigned long, Ba)
__field( unsigned long, Bb)
),
TP_fast_assign(
__entry->Aa = A->a;
__entry->Ab = A->b;
__entry->Ba = B->a;
__entry->Bb = B->b;
),
TP_printk("Aa=%ld Ab=%ld Ba=%ld Bb=%ld",
__entry->Aa, __entry->Ab, __entry->Ba, __entry->Bb)
);
#else /* !DEFINE_FULL_EVENTS */
DEFINE_EVENT(size_event_1, size_event_2,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_3,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_4,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_5,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_6,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_7,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_8,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_9,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DEFINE_EVENT(size_event_1, size_event_10,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

#endif /* !DEFINE_FULL_EVENTS */

#elif DEFINE_JUST_TRACEPOINTS

DECLARE_TRACE(size_event_1,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_2,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_3,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_4,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_5,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_6,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_7,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_8,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_9,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));

DECLARE_TRACE(size_event_10,
TP_PROTO(struct size_event_struct *A, struct size_event_struct *B),
TP_ARGS(A, B));
#endif /* DEFINE_EVENT_SIZES && DEFINE_JUST_TRACEPOINTS */

#endif

/***** NOTICE! The #if protection ends here. *****/

#undef TRACE_INCLUDE_PATH
#undef TRACE_INCLUDE_FILE
#define TRACE_INCLUDE_PATH .
#define TRACE_INCLUDE_FILE size_events
#include <trace/define_trace.h>

Next message: Xilin Wu: "[PATCH] phy: qcom-qmp-ufs: Fix HS-G4 PHY init table for sc7280"
Previous message: Lorenzo Stoakes: "Re: [PATCH v2 0/2] fix MADV_COLLAPSE issue if THP settings are disabled"
In reply to: Steven Rostedt: "Re: [PATCH v2 0/5] tracepoints: Add warnings for unused tracepoints and trace events"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]