Re: Rust in QEMU roadmap

[Daniel P . Berrangé]

On Wed, Nov 27, 2024 at 01:22:00PM +0100, Paolo Bonzini wrote:
> On Wed, Nov 27, 2024 at 1:18 PM Daniel P. Berrangé <berrange@redhat.com> 
> wrote:
> > I question the usefulness of the 'syslog' trace target. I can't see
> > it being desirable as a option for 'production' builds, and it seems
> > uneccessarily indirect for developers. What's its compelling USP ?
> >
> > WRT 'ftrace', IIUC, the Linux 'perf' command has built-in support
> > for using USDT probes now:
> >
> >   https://www.brendangregg.com/perf.html#StaticUserTracing
> 
> I also wonder if 'ftrace' is duplicating 'log' these days. Anyhow, if
> we can deprecate 'syslog' and 'ftrace' that would be good to know
> independent of Rust.

I looked back at the history of syslog and re-discovered that I raised
the same question when it was first proposed. It was said that syslog
was to be used by XenServer for some kind of logging they wanted:

  https://lists.nongnu.org/archive/html/qemu-devel/2016-08/msg00336.html

I've CC'd Paul as it'd be useful to know if Xen did end up using this
feature or not, as we don't want to rip the rug from under them.

With regards,
Daniel
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