Horton

Re: Printing backtrace of postgres processes

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, vignesh C <vignesh21@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Craig Ringer <craig.ringer@enterprisedb.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-05-06T19:55:20Z
Lists: pgsql-hackers 
Hi,

On 2021-05-06 15:22:02 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > we allow generating backtraces in all kind of places, including
> > e.g. some inside critical sections via backtrace_functions.
> 
> If there's an elog call inside a critical section, that seems
> like a problem already.  Are you sure that there are any such?

There's several, yes. In xlog.c there's quite a few that are gated by
wal_debug being enabled. But also a few without that,
e.g. XLogFileInit() logging
	elog(DEBUG1, "creating and filling new WAL file");
and XLogFileInit() can be called within a critical section.

Greetings,

Andres Freund

Commits

  1. Perform apply of large transactions by parallel workers.

  2. Enhance pg_log_backend_memory_contexts() for auxiliary processes.

  3. Allow GRANT on pg_log_backend_memory_contexts().

  4. Move Perl test modules to a better namespace

  5. Unify PostgresNode's new() and get_new_node() methods

  6. Add backtrace support for error reporting