Re: [PATCH] arm64: Add user and kernel page-fault tracepoints

[Catalin Marinas]

On Wed, Sep 09, 2026 at 06:50:58PM +0100, Leo Yan wrote:
> On Wed, Sep 09, 2026 at 01:13:42PM +0000, Bouron, Justinien wrote:
> > Thank you for the feedback. I've posted a second revision at
> > https://lore.kernel.org/lkml/20260902115216.49158-1-jbouron@xxxxxxxxxx/, though
> > it doesn't seem to be getting much traction.
> 
> This should be in the arm64 maintainers' scope (v1 caught my attention
> due to it mentioned perf related things).
> 
> I think the main question is these tracepoints overlap with perf sw
> events. Could you elaborate on why ftrace tracepoints are necessary?
> ('perf record' and 'perf script' can provide similar info and we can
> avoid extra latency).
> 
> If the maintainers think this patch is reasonable, I'd be happy to help
> test it.

I'm replying here rather than on v2.

Back in 2025, Steve and Will suggested a generic helper that emits both
the trace event and the perf event, so we don't have to call both
independently from the arch code. AFAICT, this patch (nor v2) doesn't
change this.

-- 
Catalin