From: Masami Hiramatsu (Google) <[email protected]> Add a benchmark test module (fetcharg_bench) and bench_fetcharg.sh script to measure the execution overhead of fetchargs across kprobe, fprobe, and eprobe configurations.
The benchmark runs for a baseline (no probe events), 0-arguments, 1-argument, 2-arguments, and 3-arguments configurations, calculating the estimated overhead in nanoseconds. It also supports a --debug option to dump registered dynamic events. Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu <[email protected]> --- tools/tracing/benchmark/Kbuild | 3 tools/tracing/benchmark/Makefile | 12 + tools/tracing/benchmark/bench_fetcharg.sh | 195 ++++++++++++++++++++++++ tools/tracing/benchmark/fetcharg_bench.c | 98 ++++++++++++ tools/tracing/benchmark/fetcharg_bench_trace.h | 37 +++++ 5 files changed, 345 insertions(+) create mode 100644 tools/tracing/benchmark/Kbuild create mode 100644 tools/tracing/benchmark/Makefile create mode 100755 tools/tracing/benchmark/bench_fetcharg.sh create mode 100644 tools/tracing/benchmark/fetcharg_bench.c create mode 100644 tools/tracing/benchmark/fetcharg_bench_trace.h diff --git a/tools/tracing/benchmark/Kbuild b/tools/tracing/benchmark/Kbuild new file mode 100644 index 000000000000..4c31b26ca51c --- /dev/null +++ b/tools/tracing/benchmark/Kbuild @@ -0,0 +1,3 @@ +obj-m += fetcharg_bench.o + +ccflags-y += -I$(src) diff --git a/tools/tracing/benchmark/Makefile b/tools/tracing/benchmark/Makefile new file mode 100644 index 000000000000..bf5b3cbaff03 --- /dev/null +++ b/tools/tracing/benchmark/Makefile @@ -0,0 +1,12 @@ +ifeq ($(O),) +KDIR ?= /lib/modules/$(shell uname -r)/build +else +KDIR := $(O) +endif +MDIR := $(CURDIR) + +all: + $(MAKE) -C $(KDIR) M=$(MDIR) modules + +clean: + $(MAKE) -C $(KDIR) M=$(MDIR) clean diff --git a/tools/tracing/benchmark/bench_fetcharg.sh b/tools/tracing/benchmark/bench_fetcharg.sh new file mode 100755 index 000000000000..0b2a2b8a896e --- /dev/null +++ b/tools/tracing/benchmark/bench_fetcharg.sh @@ -0,0 +1,195 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# description: Benchmark fetcharg performance (baseline vs kprobe vs fprobe vs eprobe) + +DEBUG=0 +while [[ $# -gt 0 ]]; do + case "$1" in + --debug|-d) + DEBUG=1 + shift + ;; + *) + echo "Unknown option: $1" + echo "Usage: $0 [--debug|-d]" + exit 1 + ;; + esac +done + +DEBUGFS_MOUNT=$(grep ^debugfs /proc/mounts | awk '{print $2}') +if [ -z "$DEBUGFS_MOUNT" ]; then + mount -t debugfs nodev /sys/kernel/debug + DEBUGFS_MOUNT="/sys/kernel/debug" +fi + +TRACEFS_MOUNT=$(grep ^tracefs /proc/mounts | awk '{print $2}') +if [ -z "$TRACEFS_MOUNT" ]; then + mount -t tracefs nodev /sys/kernel/tracing + TRACEFS_MOUNT="/sys/kernel/tracing" +fi + +MOD_NAME="fetcharg_bench" +MOD_FILE="./${MOD_NAME}.ko" + +if [ ! -f "$MOD_FILE" ]; then + echo "Module $MOD_FILE not found. Please run 'make' first." + exit 1 +fi + +rmmod $MOD_NAME 2>/dev/null +insmod $MOD_FILE || { echo "Failed to load $MOD_FILE"; exit 1; } + +TRIGGER_FILE="${DEBUGFS_MOUNT}/fetcharg_benchmark/trigger" + +if [ ! -f "$TRIGGER_FILE" ]; then + echo "Trigger file $TRIGGER_FILE not found." + rmmod $MOD_NAME + exit 1 +fi + +DYN_EVENTS="${TRACEFS_MOUNT}/dynamic_events" + +# Helper to clear events +clear_events() { + echo 0 > "${TRACEFS_MOUNT}/events/enable" + echo > "$DYN_EVENTS" +} + +run_bench() { + if [ "$DEBUG" = "1" ]; then + echo "=== [DEBUG] dynamic_events ===" >&2 + cat "$DYN_EVENTS" >&2 + echo "==============================" >&2 + fi + cat "$TRIGGER_FILE" +} + +calc_overhead() { + local lps=$1 + local base_lps=$2 + if [ -z "$lps" ] || [ -z "$base_lps" ] || [ "$lps" = "-" ] || [ "$base_lps" = "-" ]; then + echo "-" + return + fi + awk -v lps="$lps" -v base_lps="$base_lps" 'BEGIN { + if (lps == 0 || base_lps == 0) { + print "-" + exit + } + t = 1000000000.0 / lps + t_base = 1000000000.0 / base_lps + diff = t - t_base + printf "%.2f ns", diff + }' +} + +echo "Running Fetcharg Micro Benchmark..." +echo "Please wait, this may take a few seconds..." + +# Baseline +clear_events +baseline=$(run_bench) + +# Kprobe +clear_events +echo "p:bench_kprobe fetcharg_bench_target" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/kprobes/bench_kprobe/enable" +kprobe_0=$(run_bench) + +clear_events +echo "p:bench_kprobe fetcharg_bench_target a=\$arg1" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/kprobes/bench_kprobe/enable" +kprobe_1=$(run_bench) + +clear_events +echo "p:bench_kprobe fetcharg_bench_target a=\$arg1 b=+0(+0(\$arg2)):u32" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/kprobes/bench_kprobe/enable" +kprobe_2=$(run_bench) + +clear_events +echo "p:bench_kprobe fetcharg_bench_target a=\$arg1 b=+0(+0(\$arg2)):u32 c=+0(\$arg3):u32" \ + >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/kprobes/bench_kprobe/enable" +kprobe_3=$(run_bench) + +# Fprobe +clear_events +echo "f:bench_fprobe fetcharg_bench_target" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/fprobes/bench_fprobe/enable" +fprobe_0=$(run_bench) + +clear_events +echo "f:bench_fprobe fetcharg_bench_target a=\$arg1" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/fprobes/bench_fprobe/enable" +fprobe_1=$(run_bench) + +clear_events +echo "f:bench_fprobe fetcharg_bench_target a=\$arg1 b=+0(+0(\$arg2)):u32" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/fprobes/bench_fprobe/enable" +fprobe_2=$(run_bench) + +clear_events +echo "f:bench_fprobe fetcharg_bench_target a=\$arg1 b=+0(+0(\$arg2)):u32 c=+0(\$arg3):u32" \ + >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/fprobes/bench_fprobe/enable" +fprobe_3=$(run_bench) + +# Eprobe +clear_events +echo "e:bench_eprobe fetcharg_bench/fetcharg_bench_event" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/eprobes/bench_eprobe/enable" +echo 1 > "${TRACEFS_MOUNT}/events/fetcharg_bench/fetcharg_bench_event/enable" +eprobe_0=$(run_bench) + +clear_events +echo "e:bench_eprobe fetcharg_bench/fetcharg_bench_event a=\$a" >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/eprobes/bench_eprobe/enable" +echo 1 > "${TRACEFS_MOUNT}/events/fetcharg_bench/fetcharg_bench_event/enable" +eprobe_1=$(run_bench) + +clear_events +echo "e:bench_eprobe fetcharg_bench/fetcharg_bench_event a=\$a b=+0(+0(\$b_ptr)):u32" \ + >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/eprobes/bench_eprobe/enable" +echo 1 > "${TRACEFS_MOUNT}/events/fetcharg_bench/fetcharg_bench_event/enable" +eprobe_2=$(run_bench) + +clear_events +echo "e:bench_eprobe fetcharg_bench/fetcharg_bench_event a=\$a b=+0(+0(\$b_ptr)):u32 c=+0(\$c_ptr):u32" \ + >> "$DYN_EVENTS" +echo 1 > "${TRACEFS_MOUNT}/events/eprobes/bench_eprobe/enable" +echo 1 > "${TRACEFS_MOUNT}/events/fetcharg_bench/fetcharg_bench_event/enable" +eprobe_3=$(run_bench) + +echo "--------------------------------------------------------------------------------" +echo "Configuration 0 Fetchargs 1 Fetcharg 2 Fetchargs 3 Fetchargs" +echo "--------------------------------------------------------------------------------" +printf "%-18s %15s %15s %18s %18s loops/sec\n" "Baseline" "$baseline" "-" "-" "-" +printf "%-18s %15s %15s %18s %18s overhead\n" " " "-" "-" "-" "-" +printf "%-18s %15s %15s %18s %18s loops/sec\n" \ + "Kprobe" "$kprobe_0" "$kprobe_1" "$kprobe_2" "$kprobe_3" +printf "%-18s %15s %15s %18s %18s overhead\n" " " \ + "$(calc_overhead $kprobe_0 $baseline)" \ + "$(calc_overhead $kprobe_1 $kprobe_0)" \ + "$(calc_overhead $kprobe_2 $kprobe_0)" \ + "$(calc_overhead $kprobe_3 $kprobe_0)" +printf "%-18s %15s %15s %18s %18s loops/sec\n" \ + "Fprobe" "$fprobe_0" "$fprobe_1" "$fprobe_2" "$fprobe_3" +printf "%-18s %15s %15s %18s %18s overhead\n" " " \ + "$(calc_overhead $fprobe_0 $baseline)" \ + "$(calc_overhead $fprobe_1 $fprobe_0)" \ + "$(calc_overhead $fprobe_2 $fprobe_0)" \ + "$(calc_overhead $fprobe_3 $fprobe_0)" +printf "%-18s %15s %15s %18s %18s loops/sec\n" \ + "Eprobe" "$eprobe_0" "$eprobe_1" "$eprobe_2" "$eprobe_3" +printf "%-18s %15s %15s %18s %18s overhead\n" " " \ + "$(calc_overhead $eprobe_0 $baseline)" \ + "$(calc_overhead $eprobe_1 $eprobe_0)" \ + "$(calc_overhead $eprobe_2 $eprobe_0)" \ + "$(calc_overhead $eprobe_3 $eprobe_0)" +echo "--------------------------------------------------------------------------------" + +clear_events +rmmod $MOD_NAME +exit 0 diff --git a/tools/tracing/benchmark/fetcharg_bench.c b/tools/tracing/benchmark/fetcharg_bench.c new file mode 100644 index 000000000000..af18183c1f5d --- /dev/null +++ b/tools/tracing/benchmark/fetcharg_bench.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/module.h> +#include <linux/ktime.h> +#include <linux/debugfs.h> +#include <linux/uaccess.h> + +#define CREATE_TRACE_POINTS +#include "fetcharg_bench_trace.h" + +static noinline int fetcharg_bench_target(int a, int **b, char *c) +{ + /* Prevent compiler from optimizing the loop out entirely */ + asm volatile ("" : : "r"(a), "r"(b), "r"(c) : "memory"); + trace_fetcharg_bench_event(a, b, c); + return a + **b; +} + +/* Indirect pointer to prevent inlining */ +static int (*bench_func_ptr)(int, int **, char *) = fetcharg_bench_target; + +#define BENCH_ITERATIONS 1000000 + +static ssize_t fetcharg_bench_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + char buf[64]; + int len; + u64 start, current_time; + u64 elapsed; + u64 loops_per_sec; + int dummy = 0; + int a = 1; + int b_val = 2; + int *b_ptr = &b_val; + int **b = &b_ptr; + char c[] = "benchmark"; + int i; + + if (*ppos > 0) + return 0; /* EOF */ + + start = ktime_get_ns(); + for (i = 0; i < BENCH_ITERATIONS; i++) + dummy += bench_func_ptr(a, b, c); + current_time = ktime_get_ns(); + + elapsed = current_time - start; + loops_per_sec = ((u64)BENCH_ITERATIONS * NSEC_PER_SEC) / elapsed; + + len = snprintf(buf, sizeof(buf), "%llu\n", loops_per_sec); + if (len < 0) + return len; + + if (copy_to_user(user_buf, buf, len)) + return -EFAULT; + + *ppos += len; + + /* + * Use 'dummy' to ensure the compiler doesn't optimize out + * the call completely, though the asm volatile helps too. + */ + if (dummy == 0xdeadbeef) + pr_info("dummy=%d\n", dummy); + + return len; +} + +static const struct file_operations fetcharg_bench_fops = { + .read = fetcharg_bench_read, + .open = simple_open, + .llseek = default_llseek, +}; + +static struct dentry *bench_dir; + +static int __init fetcharg_bench_init(void) +{ + bench_dir = debugfs_create_dir("fetcharg_benchmark", NULL); + if (!bench_dir) + return -ENOMEM; + + debugfs_create_file("trigger", 0444, bench_dir, NULL, &fetcharg_bench_fops); + + return 0; +} + +static void __exit fetcharg_bench_exit(void) +{ + debugfs_remove_recursive(bench_dir); +} + +module_init(fetcharg_bench_init); +module_exit(fetcharg_bench_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Antigravity"); +MODULE_DESCRIPTION("Fetcharg performance benchmark test module"); diff --git a/tools/tracing/benchmark/fetcharg_bench_trace.h b/tools/tracing/benchmark/fetcharg_bench_trace.h new file mode 100644 index 000000000000..6560f62337e3 --- /dev/null +++ b/tools/tracing/benchmark/fetcharg_bench_trace.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM fetcharg_bench + +#if !defined(_FETCHARG_BENCH_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define _FETCHARG_BENCH_TRACE_H + +#include <linux/tracepoint.h> + +TRACE_EVENT(fetcharg_bench_event, + + TP_PROTO(int a, int **b, char *c), + + TP_ARGS(a, b, c), + + TP_STRUCT__entry( + __field(int, a) + __field(int **, b_ptr) + __field(char *, c_ptr) + ), + + TP_fast_assign( + __entry->a = a; + __entry->b_ptr = b; + __entry->c_ptr = c; + ), + + TP_printk("a=%d b=%p c=%p", __entry->a, __entry->b_ptr, __entry->c_ptr) +); + +#endif /* _FETCHARG_BENCH_TRACE_H */ + +#undef TRACE_INCLUDE_PATH +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE fetcharg_bench_trace +#include <trace/define_trace.h>
