On 2023/12/9 23:23, Jakub Jelinek wrote: > On Sat, Dec 09, 2023 at 10:39:45AM -0500, Lipeng Zhu wrote: > > This patch try to introduce the rwlock and split the read/write to > > unit_root tree and unit_cache with rwlock instead of the mutex to > > increase CPU efficiency. In the get_gfc_unit function, the percentage > > to step into the insert_unit function is around 30%, in most > > instances, we can get the unit in the phase of reading the unit_cache > > or unit_root tree. So split the read/write phase by rwlock would be an > > approach to make it more parallel. > > > > BTW, the IPC metrics can gain around 9x in our test server with 220 > > cores. The benchmark we used is https://github.com/rwesson/NEAT > > > > libgcc/ChangeLog: > > > > * gthr-posix.h (__GTHREAD_RWLOCK_INIT): New macro. > > (__gthrw): New function. > > (__gthread_rwlock_rdlock): New function. > > (__gthread_rwlock_tryrdlock): New function. > > (__gthread_rwlock_wrlock): New function. > > (__gthread_rwlock_trywrlock): New function. > > (__gthread_rwlock_unlock): New function. > > > > libgfortran/ChangeLog: > > > > * io/async.c (DEBUG_LINE): New macro. > > * io/async.h (RWLOCK_DEBUG_ADD): New macro. > > (CHECK_RDLOCK): New macro. > > (CHECK_WRLOCK): New macro. > > (TAIL_RWLOCK_DEBUG_QUEUE): New macro. > > (IN_RWLOCK_DEBUG_QUEUE): New macro. > > (RDLOCK): New macro. > > (WRLOCK): New macro. > > (RWUNLOCK): New macro. > > (RD_TO_WRLOCK): New macro. > > (INTERN_RDLOCK): New macro. > > (INTERN_WRLOCK): New macro. > > (INTERN_RWUNLOCK): New macro. > > * io/io.h (struct gfc_unit): Change UNIT_LOCK to UNIT_RWLOCK in > > a comment. > > (unit_lock): Remove including associated internal_proto. > > (unit_rwlock): New declarations including associated internal_proto. > > (dec_waiting_unlocked): Use WRLOCK and RWUNLOCK on unit_rwlock > > instead of __gthread_mutex_lock and __gthread_mutex_unlock on > > unit_lock. > > * io/transfer.c (st_read_done_worker): Use WRLOCK and RWUNLOCK > on > > unit_rwlock instead of LOCK and UNLOCK on unit_lock. > > (st_write_done_worker): Likewise. > > * io/unit.c: Change UNIT_LOCK to UNIT_RWLOCK in 'IO locking rules' > > comment. Use unit_rwlock variable instead of unit_lock variable. > > (get_gfc_unit_from_unit_root): New function. > > (get_gfc_unit): Use RDLOCK, WRLOCK and RWUNLOCK on unit_rwlock > > instead of LOCK and UNLOCK on unit_lock. > > (close_unit_1): Use WRLOCK and RWUNLOCK on unit_rwlock instead > of > > LOCK and UNLOCK on unit_lock. > > (close_units): Likewise. > > (newunit_alloc): Use RWUNLOCK on unit_rwlock instead of UNLOCK on > > unit_lock. > > * io/unix.c (find_file): Use RDLOCK and RWUNLOCK on unit_rwlock > > instead of LOCK and UNLOCK on unit_lock. > > (flush_all_units): Use WRLOCK and RWUNLOCK on unit_rwlock instead > > of LOCK and UNLOCK on unit_lock. > > Ok for trunk, thanks. > > Jakub
Thanks! Looking forward to landing to trunk. Lipeng Zhu
