Re: BUG #16707: Memory leak

Hi,

On 2020-11-09 17:20:37 -0500, Tom Lane wrote:
> Kurt Roeckx <kurt@roeckx.be> writes:
> > Grand total: 3575000 bytes in 533 blocks; 596232 free (450 chunks); 2978768 used
> 
> > Which was for this process:
> > USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
> > postgres 10000  2.6 16.3 5547172 5374656 ?     Ss   Nov08  54:10 postgres: synapse synapse [local] idle
> 
> Hm.  It would seem that whatever you're leaking was not allocated via
> palloc.  Have you got any extensions loaded into that backend?
> 
> It's also worth noting that if you've got 4GB of shared buffers,
> a total process vsize of 5.3GB doesn't seem all that far out of
> line.  I'm not quite convinced that you have a leak at all,
> as opposed to processes gradually touching more and more of the
> shared buffer arena.

As this is on a halfway recent linux, I suggest doing something like

$ grep ^Rss /proc/$pid/status
RssAnon:        6664 kB
RssFile:       69512 kB
RssShmem:       15788 kB

Anon are allocations and some other small stuff, RssFile is memory
mapped files, shmem is shared memory (but 0 when huge pages are used).

Greetings,

Andres Freund