Re: using rhashtable in inethash

From: Thomas Graf <tgraf@suug.ch>
Date: Tue, 26 Aug 2014 00:33:46 +0100

The reason I added added the sync is because I could not see how
else to prevent the sock_put() in netlink_release() to release
socket memoray, specifically the embedded rhash_head, that is
possibly being accessed in a RCU protected reader traversing the
bucket. Such a reader would not hold a reference to the socket.
I may be missing something though and I'm happy to change this for
something better.

Ok, this is going to be a tree-wide issue where we try to use
rhashtable with sockets of any type.

Perhaps we're overdue for RCU freeing of sockets, but that added
noticable latency last time I tried it.