On Fri, Apr 22, 2016 at 06:03:02PM -0700, Daniele Di Proietto wrote: > ovs_mutex_cond_wait() is used in many functions in dpif-netdev to > synchronize with pmd threads, but we can't guarantee that the callers do > not hold RCU references, so it's better to avoid quiescing. > > In system_stats_thread_func() the code relied on ovs_mutex_cond_wait() > to introduce a quiescent state, so explicit calls to > ovsrcu_quiesce_start() and ovsrcu_quiesce_end() are added there. > > Signed-off-by: Daniele Di Proietto <diproiet...@vmware.com>
This seems reasonable to me, but I recommend adding a comment on ovs_mutex_cond_wait() suggesting that the caller quiesce, so that it's harder to get that wrong in the future: /* Provides an error-checking wrapper around pthread_cond_wait(). * * If the wait can take a significant amount of time, consider bracketing this * call with calls to ovsrcu_quiesce_start() and ovsrcu_quiesce_end(). */ Acked-by: Ben Pfaff <b...@ovn.org> (I'm not planning to review the other patches, I'm reviewing this one because Daniele asked me to look at it.) Thanks, Ben. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
