Re: [v2 PATCH 7/10] rhashtable: Disable automatic shrinking

From: Thomas Graf <tgraf@suug.ch>
Date: Mon, 23 Mar 2015 08:33:19 +0000

I don't get why almost nobody would want shrinking. I agree that for
tables like TCP hash tables, once you have grown you want to keep that
table size because the load is likely to come back. But we will also
have lots of users such as the Netlink socket with a table per protocol
where not shrinking results in giving the user the ability to waste
memory indefinitely for no gain.

The user can't do this with TCP?  Why is netlink only susceptible?

The only plausible argument for shrinking I've ever heard of is the
nft_hash case, and there that code can _explicitly_ ask for a shrink
after it has made a major table modification.

That puts all of the smarts for when to shrink where the knowledge
resides, and in this case that's the user.