Re: [PATCH v10 07/14] unwind_user/deferred: Make unwind deferral requests NMI-safe

[Steven Rostedt]

On June 19, 2025 4:48:13 AM EDT, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>On Thu, Jun 19, 2025 at 10:44:27AM +0200, Peter Zijlstra wrote:
>
>> Luckily, x86 dropped support for !CMPXCHG8B right along with !TSC. So on
>> x86 we good with timestamps, even on 32bit.
>
>Well, not entirely true, local_clock() is not guaranteed monotonic. So
>you might be in for quite a bit of hurt if you rely on that.
>

As long as it is monotonic per task. If it is not, then pretty much all tracers that use it are broken.

-- Steve