Sent this with screenshot attached first but don't think the list supports that... So here's a screenshot from instruments after running for a few mins.
On Tue, Nov 21, 2017 at 12:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Can you get a profile of where the machine is spending its time during the dump run? On Linux I'd recommend "perf", but on macOS, hmm ... You could use Activity Monitor, but as far as I can see that just captures short-duration snapshots, which might not be representative of a 10-hour run. XCode's Instruments feature would probably be better about giving a full picture, but it has a steep learning curve.
macOS's "sample" is pretty easy to use and produces text format output that is easy to email.
Ah, good idea. But note that only traces one process, so you'd need to first determine whether it's pg_dump or the backend that's eating most of the CPU. Or sample both of them.