> I see no attachment here, but isn't this because Emacs never returns
> memory to the system when it frees it?

Sorry, I forgot to send the attachment in the first message. I have sent
a followup, but also attaching here just in case.

What you say about Emacs not returning memory sounds like very very
strange behaviour unless I misunderstand something. Does it mean that if
I have emacs running as daemon and open a few hundreds of heavy pdfs
during, say, a week, it will keep all the memory allocated for those pdfs
(which is several Gb, at least)? If so, I don't think that Emacs should
do it.

Regards,
Ihor