Subject: Re: [PATCH v11 1/2] kunit: add tests for smp_cond_load_*_timeout()

From: Andrew Morton <[email-masked]>
Date: Thu, 21 May 2026 14:46:29 -0700

On Thu, 21 May 2026 01:30:37 -0700 Ankur Arora <[email-masked]> wrote:

> Add success and failure case tests for smp_cond_load_*_timeout().
> 
> All of the test cases wait on some state in smp_cond_load_*_timeout().
> In the success case we spawn a kthread that pokes the bit.
> 
> Success or failure cases depend on the expected bit being set (or not).
> Additionally in failure cases smp_cond_load_*_timeout() cannot return
> before timeout.

Your title "kunit: ..." implies that this is a kunit patchset.  ie, and
to my mind, this implies that the patchset makes changes to kunit
infrastructure.  This isn't the case, of course.

>
> ...
>  
> +config BARRIER_TIMEOUT_TEST
> +	tristate "KUnit tests for smp_cond_load_relaxed_timeout()"

The patchset which attempted to add smp_cond_load_relaxed_timeout() was
titled "barrier: ...", which is a more appropriate identifier for this
patchset.

Anyway, I removed the series "barrier: Add
smp_cond_load_{relaxed,acquire}_timeout()" from mm.git on May 19 for
forgotten reasons.  So I suggest that the series be respun and resent,
with these two test patches included.

Again, I'm really not the guy to be handling these patches.  But a 4-6%
performance improvement in real world workloads is not to be ignored.

Not by me, anyway.