Re: [PATCH v11 14/26] locking/lockdep, cpu/hotplus: Use a weaker annotation in AP thread

On Mon, Feb 12, 2024 at 04:16:41PM +0100, Thomas Gleixner wrote:

On Tue, Jan 30 2024 at 11:58, Byungchul Park wrote:

quoted

On Fri, Jan 26, 2024 at 06:30:02PM +0100, Thomas Gleixner wrote:

quoted

On Wed, Jan 24 2024 at 20:59, Byungchul Park wrote:

Why is lockdep in the subsystem prefix here? You are changing the CPU
hotplug (not hotplus) code, right?

quoted

cb92173d1f0 ("locking/lockdep, cpu/hotplug: Annotate AP thread") was
introduced to make lockdep_assert_cpus_held() work in AP thread.

However, the annotation is too strong for that purpose. We don't have to
use more than try lock annotation for that.

This lacks a proper explanation why this is too strong.

quoted

Furthermore, now that Dept was introduced, false positive alarms was
reported by that. Replaced it with try lock annotation.

I still have zero idea what this is about.

1. can track PG_locked that is a potential deadlock trigger.

   https://lore.kernel.org/lkml/1674268856-31807-1-git-send-email-byungchul.park@lge.com/ (local)

Sure, but that wants to be explicitely explained in the changelog and
not with a link. 'Now that Dept was introduced ...' is not an
explanation.

Admit. I will fix it from the next spin. Thanks.

	Byungchul