Re: BUG #16707: Memory leak

Hi,

On 2020-11-10 09:11:20 +0100, Kurt Roeckx wrote:
> On Mon, Nov 09, 2020 at 08:31:27PM -0800, Andres Freund wrote:
> > 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
>
> RssAnon: 1197064 kB
> RssFile: 27420 kB
> RssShmem: 4248052 kB

Ok, so it's actual allocations that are the problem. What kind of
queries is this workload running?

There's one known (slow) memory leak in the JIT code / LLVM. Could you
check if the issue vanishes if you disable JIT (jit = 0)?

Otherwise it might be useful to collect stack traces for memory
allocations. You could try something like 'heaptrack' or add a perf
probe on malloc, and do a perf profile.

E.g. something like
perf probe -x /lib/x86_64-linux-gnu/libc.so.6 -a malloc
perf record -e probe_libc:malloc --call-graph dwarf -p $pid_of_problematic_process

Regards,

Andres