Re: [PATCH v1 0/4] selftests/ftrace: Add a boottime tracing test framework

On Mon, 10 Aug 2026 10:53:00 -0400
Steven Rostedt [off-list ref] wrote:

On Mon, 10 Aug 2026 18:33:45 +0900
"Masami Hiramatsu (Google)" [off-list ref] wrote:

quoted

Hi,

This series adds a boottime tracing test framework to selftests/ftrace.
This is based on v3 series[1] of the boot-time trace (via bootconfig)
testing script.

[1] https://lore.kernel.org/all/178613904128.259829.16130019979800943264.stgit@devnote2/ (local)

The new run_boottime_test.sh can run tests not only for boottime trace
but also other kernel cmdline tracing options, including persistent
ring buffer and its backup.
This makes it possible to easily detect regression bugs in the kernel
boot trace options.

Here is an example of the test output.
-----
TAP version 13
1..14
ok 1 01-kprobe
ok 2 02-synth
ok 3 03-eprobe
ok 4 04-fprobe
ok 5 05-tprobe
ok 6 06-instance
ok 7 cmdline-01-ftrace
ok 8 cmdline-02-trace-event
ok 9 cmdline-03-trace-buf-size
ok 10 cmdline-04-trace-options
ok 11 cmdline-05-trace-clock
ok 12 cmdline-06-trace-instance
ok 13 persistent-01-reserve-mem
ok 14 persistent-02-backup-instance
# Totals: pass:14 fail:0 xfail:0 xpass:0 skip:0 error:0
-----

Just to understand this better. This series creates a small ramdisk and
runs qemu on a given kernel to boot in qemu and test, right?

Yes, that's right.

Can you add the examples you have in the documentation patch to the cover
letter. That will market more exactly what you are doing.

OK, let me update the series with the explanation.

Thank you!

-- Steve

-- 
Masami Hiramatsu (Google) [off-list ref]