Re: [PATCH] Identify LWLocks in tracepoints

Peter Eisentraut <peter.eisentraut@enterprisedb.com>

From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
To: Craig Ringer <craig.ringer@enterprisedb.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-03-22T09:00:39Z
Lists: pgsql-hackers
On 20.03.21 01:29, Craig Ringer wrote:
>     There is already support for that.  See the documentation at the end of
>     this page:
>     https://www.postgresql.org/docs/devel/dynamic-trace.html#DEFINING-TRACE-POINTS
>     <https://www.postgresql.org/docs/devel/dynamic-trace.html#DEFINING-TRACE-POINTS>
> 
> 
> Pretty sure it won't work right now.
> 
> To use systemtap semaphores (the _ENABLED macros) you need to run dtrace 
> -g to generate a probes.o then link that into postgres.
> 
> I don't think we do that. I'll double check soon.

We do that.  (It's -G.)



Commits

  1. Emit dummy statements for probes.d probes when disabled

  2. Prevent lwlock dtrace probes from unnecessary work

  3. doc: Fix typo in logicaldecoding.sgml.

  4. Move lwlock-release probe back where it belongs

  5. Remove bogus tracepoint

  6. Simplify LWLock tranche machinery by removing array_base/array_stride.

  7. Improve LWLock scalability.