From mboxrd@z Thu Jan 1 00:00:00 1970 From: jlayton@poochiereds.net (Jeff Layton) Date: Sat, 25 Apr 2015 17:29:02 -0400 Subject: [lttng-dev] cds_lfht_count_nodes always returns -1 for before/after counts Message-ID: <20150425172902.08ca0cdc@tlielax.poochiereds.net> Hi, I have some code using the cds_lfht infrastructure, and recently added a function to check to see if the table was empty using cds_lfht_count_nodes. That function just does this: rcu_read_lock(); cds_lfht_count_nodes(ht, &before, &count, &after); rcu_read_unlock(); What I've found though is that when the table is empty and I know that there are no concurrent inserts going on, the before and after counters are always set to -1 after this call. Is that expected behavior? For the record, I'm using this package from the Fedora 21 repos: userspace-rcu-0.8.1-5.fc21.x86_64 Thanks in advance! -- Jeff Layton