linux/samples/Makefile
Mark Rutland b56c68f705 ftrace: Add sample with custom ops
When reworking core ftrace code or architectural ftrace code, it's often
necessary to test/analyse/benchmark a number of ftrace_ops
configurations. This patch adds a module which can be used to explore
some of those configurations.

I'm using this to benchmark various options for changing the way
trampolines and handling of ftrace_ops work on arm64, and ensuring other
architectures aren't adversely affected.

For example, in a QEMU+KVM VM running on a 2GHz Xeon E5-2660
workstation, loading the module in various configurations produces:

| # insmod ftrace-ops.ko
| ftrace_ops: registering:
|   relevant ops: 1
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 0
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: NO
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1681558ns (16ns / call)

| # insmod ftrace-ops.ko nr_ops_irrelevant=5
| ftrace_ops: registering:
|   relevant ops: 1
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 5
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: NO
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1693042ns (16ns / call)

| # insmod ftrace-ops.ko nr_ops_relevant=2
| ftrace_ops: registering:
|   relevant ops: 2
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 0
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: NO
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 11965582ns (119ns / call)

| # insmod ftrace-ops.ko save_regs=true
| ftrace_ops: registering:
|   relevant ops: 1
|     tracee: tracee_relevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   irrelevant ops: 0
|     tracee: tracee_irrelevant [ftrace_ops]
|     tracer: ops_func_nop [ftrace_ops]
|   saving registers: YES
|   assist recursion: NO
|   assist RCU: NO
| ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 4459624ns (44ns / call)

Link: https://lkml.kernel.org/r/20230103124912.2948963-4-mark.rutland@arm.com

Cc: Florent Revest <revest@chromium.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-01-25 10:31:23 -05:00

40 lines
1.6 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# Makefile for Linux samples code
subdir-$(CONFIG_SAMPLE_AUXDISPLAY) += auxdisplay
subdir-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs
obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs/
obj-$(CONFIG_SAMPLE_CONNECTOR) += connector/
obj-$(CONFIG_SAMPLE_FANOTIFY_ERROR) += fanotify/
subdir-$(CONFIG_SAMPLE_HIDRAW) += hidraw
obj-$(CONFIG_SAMPLE_HW_BREAKPOINT) += hw_breakpoint/
obj-$(CONFIG_SAMPLE_KDB) += kdb/
obj-$(CONFIG_SAMPLE_KFIFO) += kfifo/
obj-$(CONFIG_SAMPLE_KOBJECT) += kobject/
obj-$(CONFIG_SAMPLE_KPROBES) += kprobes/
subdir-$(CONFIG_SAMPLE_LANDLOCK) += landlock
obj-$(CONFIG_SAMPLE_LIVEPATCH) += livepatch/
subdir-$(CONFIG_SAMPLE_PIDFD) += pidfd
obj-$(CONFIG_SAMPLE_QMI_CLIENT) += qmi/
obj-$(CONFIG_SAMPLE_RPMSG_CLIENT) += rpmsg/
subdir-$(CONFIG_SAMPLE_SECCOMP) += seccomp
subdir-$(CONFIG_SAMPLE_TIMER) += timers
obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace_events/
obj-$(CONFIG_SAMPLE_TRACE_CUSTOM_EVENTS) += trace_events/
obj-$(CONFIG_SAMPLE_TRACE_PRINTK) += trace_printk/
obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace/
obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace/
obj-$(CONFIG_SAMPLE_FTRACE_OPS) += ftrace/
obj-$(CONFIG_SAMPLE_TRACE_ARRAY) += ftrace/
subdir-$(CONFIG_SAMPLE_UHID) += uhid
obj-$(CONFIG_VIDEO_PCI_SKELETON) += v4l/
obj-y += vfio-mdev/
subdir-$(CONFIG_SAMPLE_VFS) += vfs
obj-$(CONFIG_SAMPLE_INTEL_MEI) += mei/
subdir-$(CONFIG_SAMPLE_WATCHDOG) += watchdog
subdir-$(CONFIG_SAMPLE_WATCH_QUEUE) += watch_queue
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak/
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight/
obj-$(CONFIG_SAMPLE_FPROBE) += fprobe/
obj-$(CONFIG_SAMPLES_RUST) += rust/