Re: [PATCH v5 1/2] printk: Add console owner and waiter logic to load balance console writes

From: Steven Rostedt
Date: Thu Jan 18 2018 - 19:20:40 EST


On Thu, 18 Jan 2018 23:03:24 +0100
Pavel Machek <pavel@xxxxxx> wrote:


> > To demonstrate the issue, this module has been shown to lock up a
> > system with 4 CPUs and a slow console (like a serial console). It is
> > also able to lock up a 8 CPU system with only a fast (VGA) console, by
> > passing in "loops=100". The changes in this commit prevent this module
> > from locking up the system.
> >
> > #include <linux/module.h>
> > #include <linux/delay.h>
> > #include <linux/sched.h>
> > #include <linux/mutex.h>
> > #include <linux/workqueue.h>
> > #include <linux/hrtimer.h>
>
> Programs in commit messages. Not preffered way to distribute code, I'd
> say. What about putting it into kernel selftests directory or
> something like that?

It's not really a program, but a module. I could add a real module that
can test this, and people can modprobe it if they want to make sure
there's no regressions.

I can send a patch.

-- Steve