On Thu, 2018-02-22 at 04:19 +0000, Damien Le Moal wrote: > It looks OK to me, at least if CONFIG_DEBUG_OBJECTS_RCU_HEAD is turned > off since the init_rcu_head() and destroy_rcu_head() functions only care > about that. > > With rcu head debug turned on, I am not so sure. The object debug code > will have references to unused rcu heads left behind for unused scsi > cmds, which are indeed dynamically allocated for a device together with > requests when the device is initialized, but they are never freed until > the device is removed. So "dynamically allocated object", yes, but that > does not match the use of the object done in scsi (i.e. alloc before use > + free after use). Hello Damien, Please have a look at the following part of Documentation/RCU/Design/Requirements/Requirements.html: Similarly, statically allocated non-stack <tt>rcu_head</tt> structures must be initialized with <tt>init_rcu_head()</tt> and cleaned up with <tt>destroy_rcu_head()</tt>. Thanks, Bart.