Re: Is there a memory leak in commit 8561e48?

On 4/19/18 02:10, Michael Paquier wrote:
> On Thu, Apr 19, 2018 at 11:38:09AM +0800, jian.long@i-soft.com.cn wrote:
>> in commit 8561e48, _SPI_stack alloc from TopMemoryContext. But
>> AtEOXact_SPI just set _SPI_stack = NULL. Is this a memory leak? 
> 
> You are right.  I can easily see the leak if I use for example a
> background worker which connects to a database, and launches many
> transactions in a row.  The laziest reproducer I have is to patch one of
> my bgworkers to launch millions of transactions in a tight loop and the
> leak is plain (this counts relations automatically, does not matter):
> https://github.com/michaelpq/pg_plugins/tree/master/count_relations

This is not a memory leak in the sense that the memory is not reusable.
It allocates memory for a stack, and that stack will be reused later.
The stack could be bigger than you'll need, but that's not necessarily a
problem.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services