Re: [PATCH RESEND] x86/split_lock: Warn for bus locks once for each task

From: Pedro Falcato
Date: Wed Sep 17 2025 - 11:38:40 EST


On Wed, Sep 17, 2025 at 05:41:11PM +0300, Maksim Davydov wrote:
> Hi!

Hi!

> I've tested this patch (VM w/ bus lock detection and w/o split lock
> detection). The warn mode works fine and as expected with only one
> notification per task. However, the ratelimit mode has been changed too:
> only one notification per task will be in dmesg, because this mode reuses
> notification code of warn mode. But in the documentation for ratelimit mode
> there is nothing about the limit of notifications: "Limit bus lock rate to N
> bus locks per second system wide and warn on bus locks.". Thus, I think that
> ratelimit mode should remain old behaviour.
>

So, you're suggesting different "warn" behaviors depending on =warn vs
=ratelimit? I don't have a particularly strong opinion here, but I was assuming
that "warn on bus locks" means "do whatever =warn is supposed to do". I'm not
sure warning every time gains you much, though.

--
Pedro