Re: [PATCH v1] kernel: add a simple timer based software watchpoint

["David Hildenbrand (Arm)" <david@kernel.org>]

On 6/24/26 11:04, Thomas Gleixner wrote:
> On Tue, Jun 23 2026 at 16:26, Feng Tang wrote:
>> On Mon, Jun 22, 2026 at 04:13:37PM +0200, David Hildenbrand (Arm) wrote:
>> As discussed in RFC patch review, this debug feature is similar to
>> soft/hard lockup detector and task-hung detector, should I make the control
> 
> How is this very specialized ad hoc debug magic in any way similar to
> generally useful and just working debug mechanism like the lockup or
> hung detector? Those are just turned on, do not need a boatload of
> command line parameters and are generally useful.
> 
> Your debug magic is a workaround for a disfunctional hardware debugger,
> which means it's going to be used by three people twice a year if at
> all. Seriously?

Jup.

As a side note, I worked on hw/sw breakpoint support for VMs in QEMU in the past.

So if the problem can be reproduced in a VM, there is the possible alternative
of attaching gdb to the gdbserver in QEMU and setting hw/sw breakpoints,
including watchpoints. It's primarily focused on memory accesses, of course (not
mmio).

-- 
Cheers,

David