[PATCH v2] ARM, ARM64, LONGARCH: Delay HW BP notification to task_work()

[Sebastian Andrzej Siewior]

On 2026-09-03 13:31:46 [-0400], Steven Rostedt wrote:
> On Thu, 3 Sep 2026 17:47:24 +0100
> Russell King <linux at armlinux.org.uk> wrote:
> 
> > What do you expect to happen with this? Which arch maintainer should
> > apply this patch that affects three different independently maintained
> > architectures?

Well, if you as the ARM person are fine with ARM part, an ACK would be
appreciated. If you have something to object, it would be nice to let me
know so I can adjust accordingly.

> Looks like the patch should be broken up into a 4 part series.
> 
> One to add the ARCH_NEED_PERF_HW_NOTIF code to the generic code.
> 
> Then one for each architecture to add the code needed to set that.
> 
> Then the architecture maintainers could ack their patch and the perf
> maintainer can pull it all in.

We could first agree if this is the right way of fixing it (from both,
perf side and ARCH side).
Then we could either route this via perf with ARCH's acks or split it
and route via individual trees if needed. Having it routed separately 
needs to be coordinated since the ARCH bits can't be applied without
having the perf bits first.
Then there is also the question if this should get fixes tag on commit
d8fccd9ca5f90 ("arm64: Allow to enable PREEMPT_RT.") (which would also
cover loongarch and arm).

As of today I have just Luis responding that it works for him. 

> -- Steve

Sebastian