On Sat, Feb 01, 2020 at 02:23:24AM +0000, Taylor R Campbell wrote: > Module Name: src > Committed By: riastradh > Date: Sat Feb 1 02:23:23 UTC 2020 > > Modified Files: > src/sys/ddb: db_xxx.c > src/sys/kern: kern_descrip.c kern_sig.c subr_exec_fd.c uipc_socket2.c > uipc_usrreq.c > > Log Message: > Load struct fdfile::ff_file with atomic_load_consume. > > Exceptions: when we're only testing whether it's there, not about to > dereference it. > > Note: We do not use atomic_store_release to set it because the > preceding mutex_exit should be enough. > > (That said, it's not clear the mutex_enter/exit is needed unless > refcnt > 0 already, in which case maybe it would be a win to switch > from the membar implied by mutex_enter to the membar implied by > atomic_store_release -- which I would generally expect to be much > cheaper. And a little clearer without a long comment.)
Likely procfs and sysctl since they go the strongly-locked route. Andrew