Re: [PATCH net-next 3/3] nftables: Convert nft_hash to use generic rhashtable

On 08/01/14 at 11:17am, Patrick McHardy wrote:

On 1. August 2014 09:52:00 GMT+01:00, Thomas Graf [off-list ref] wrote:

quoted

If the set size is known in advance, the table is sized accordingly,
otherwise the table size will default to 64. This is a slight change
in behaviour as previously the default was 4 which eventually required
many expansion iterations.

That's assuming a sufficient number of entries will be added. I think there
will be many cases in nftables where the number will be lower. Since
expansion is not very expansive this number was chosen very deliberately
and I'd prefer to keep it.

Other than that:

Acked-by: Patrick McHardy <redacted>

OK, I will change the nft_hash default size back to 4.

I think the expansion is more expensive than it looks though as we
are potentially calling synchronize_rcu() multiple times while
holding a mutex to protect from concurrent mutations.