Horton

Re: [PATCH] Identify LWLocks in tracepoints

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Andres Freund <andres@anarazel.de>, Craig Ringer <craig.ringer@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-05-08T17:13:47Z
Lists: pgsql-hackers 
Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
> On 05.05.21 00:15, Andres Freund wrote:
>> I'm now getting
>> /home/andres/src/postgresql/src/backend/storage/lmgr/lwlock.c: In function ‘LWLockAcquire’:
>> /home/andres/src/postgresql/src/backend/storage/lmgr/lwlock.c:1322:58: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
>> 1322 |    TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), mode);
>> |                                                          ^

> What compiler are you using in this situation?

All of these buildfarm members are now showing this warning:

calliphoridae	gcc (Debian 10.1.0-6) 10.1.0
culicidae	gcc (Debian 10.1.0-6) 10.1.0
flaviventris	gcc (Debian 20200124-1) 10.0.1 20200124 (experimental)
francolin	gcc (Debian 10.1.0-6) 10.1.0
piculetœ	gcc (Debian 10.1.0-6) 10.1.0
rorqual		gcc (Debian 10.1.0-6) 10.1.0
serinus		gcc (Debian 20200124-1) 10.0.1 20200124 (experimental)
skink		gcc (Debian 10.1.0-6) 10.1.0

so there's your answer.

(I wonder why flaviventris and serinus are still using an "experimental"
compiler version that is now behind mainstream.)

			regards, tom lane

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.