Re: [PATCH proxmox 1/6] log: replace per layer filtering by one global filter

["Thomas Ellmenreich" <t.ellmenreich@proxmox.com>]

On Mon Oct 12, 2026 at 3:20 PM CEST, Gabriel Goller wrote:
>> [snip]
>> @@ -153,10 +135,13 @@ impl Logger {
>>      ///
>>      /// Also configures the `LogTracer` which will convert all `log` events to tracing events.
>>      pub fn init(self) -> Result<(), anyhow::Error> {
>> -        let registry = tracing_subscriber::registry().with(self.layer);
>> +        let registry = tracing_subscriber::registry()
>> +            .with(self.layer)
>> +            .with(self.global_log_level);
>> +
>>          tracing::subscriber::set_global_default(registry)?;
>>  
>> -        LogTracer::init_with_filter(self.global_log_level.as_log())?;
>> +        LogTracer::init()?;
>
> Hmm any reason why this was changed?
> I'm asking because this means all the log invocations (there aren't many though)
> will build a whole tracing record before being filtered by the level filter.
> When passing a global log level to the LogTracer, all the levels below will be
> optimized away.
>
> I'm a bit afraid that there is a crate that has a log::debug! statement in the
> hot-path in a loop somewhere -- that would mean we create a whole tracing record
> and discard it on every debug! :)
>
> Note sure if this is a big issue though -- we have very few log invocations
> anyway and other crates shouldn't be such a big issue.

Thanks for pointing this out!

I removed it thinking that it was completely unnecessary, but what you
mentioned would indeed be interesting. My main reason for removing it was
to avoid duplicate filter addition, but I now realise that tracing_log
would not have respected the tracing_subscriber::filter::EnvFilter so
easily. I will check what the best approach here could be and then post
the next version.

Again, thanks for pointing this out ;)

>
>>          Ok(())
>>      }
>>  }
>> --