K 10 svn:author V 4 jeff K 8 svn:date V 27 2020-01-04T03:04:46.836669Z K 7 svn:log V 496 Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827 END