Author: mjg Date: Fri Jan 24 07:42:57 2020 New Revision: 357069 URL: https://svnweb.freebsd.org/changeset/base/357069
Log: lockmgr: don't touch the lock past unlock This evens it up with other locking primitives. Note lock profiling still touches the lock, which again is in line with the rest. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23343 Modified: head/sys/kern/kern_lock.c Modified: head/sys/kern/kern_lock.c ============================================================================== --- head/sys/kern/kern_lock.c Fri Jan 24 06:24:40 2020 (r357068) +++ head/sys/kern/kern_lock.c Fri Jan 24 07:42:57 2020 (r357069) @@ -209,7 +209,6 @@ static void lockmgr_note_shared_release(struct lock *lk, const char *file, int line) { - LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_READER); WITNESS_UNLOCK(&lk->lock_object, 0, file, line); LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, file, line); TD_LOCKS_DEC(curthread); @@ -234,11 +233,12 @@ static void lockmgr_note_exclusive_release(struct lock *lk, const char *file, int line) { - LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_WRITER); + if (LK_HOLDER(lk->lk_lock) != LK_KERNPROC) { + WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); + TD_LOCKS_DEC(curthread); + } LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, lk->lk_recurse, file, line); - WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); - TD_LOCKS_DEC(curthread); } static __inline struct thread * @@ -388,7 +388,7 @@ retry_sleepq: break; } - lockmgr_note_shared_release(lk, file, line); + LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_READER); return (wakeup_swapper); } @@ -924,6 +924,7 @@ lockmgr_upgrade(struct lock *lk, u_int flags, struct l * We have been unable to succeed in upgrading, so just * give up the shared lock. */ + lockmgr_note_shared_release(lk, file, line); wakeup_swapper |= wakeupshlk(lk, file, line); error = lockmgr_xlock_hard(lk, flags, ilk, file, line, lwa); flags &= ~LK_INTERLOCK; @@ -1034,11 +1035,6 @@ lockmgr_xunlock_hard(struct lock *lk, uintptr_t x, u_i */ if (LK_HOLDER(x) == LK_KERNPROC) tid = LK_KERNPROC; - else { - WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); - TD_LOCKS_DEC(curthread); - } - LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, lk->lk_recurse, file, line); /* * The lock is held in exclusive mode. @@ -1135,16 +1131,18 @@ lockmgr_unlock_fast_path(struct lock *lk, u_int flags, _lockmgr_assert(lk, KA_LOCKED, file, line); x = lk->lk_lock; if (__predict_true(x & LK_SHARE) != 0) { + lockmgr_note_shared_release(lk, file, line); if (lockmgr_sunlock_try(lk, &x)) { - lockmgr_note_shared_release(lk, file, line); + LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_READER); } else { return (lockmgr_sunlock_hard(lk, x, flags, ilk, file, line)); } } else { tid = (uintptr_t)curthread; + lockmgr_note_exclusive_release(lk, file, line); if (!lockmgr_recursed(lk) && atomic_cmpset_rel_ptr(&lk->lk_lock, tid, LK_UNLOCKED)) { - lockmgr_note_exclusive_release(lk, file, line); + LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_WRITER); } else { return (lockmgr_xunlock_hard(lk, x, flags, ilk, file, line)); } @@ -1221,16 +1219,18 @@ lockmgr_unlock(struct lock *lk) _lockmgr_assert(lk, KA_LOCKED, file, line); x = lk->lk_lock; if (__predict_true(x & LK_SHARE) != 0) { + lockmgr_note_shared_release(lk, file, line); if (lockmgr_sunlock_try(lk, &x)) { - lockmgr_note_shared_release(lk, file, line); + LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_READER); } else { return (lockmgr_sunlock_hard(lk, x, LK_RELEASE, NULL, file, line)); } } else { tid = (uintptr_t)curthread; + lockmgr_note_exclusive_release(lk, file, line); if (!lockmgr_recursed(lk) && atomic_cmpset_rel_ptr(&lk->lk_lock, tid, LK_UNLOCKED)) { - lockmgr_note_exclusive_release(lk, file, line); + LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_WRITER); } else { return (lockmgr_xunlock_hard(lk, x, LK_RELEASE, NULL, file, line)); } @@ -1347,8 +1347,10 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lo x = lk->lk_lock; if (__predict_true(x & LK_SHARE) != 0) { + lockmgr_note_shared_release(lk, file, line); return (lockmgr_sunlock_hard(lk, x, flags, ilk, file, line)); } else { + lockmgr_note_exclusive_release(lk, file, line); return (lockmgr_xunlock_hard(lk, x, flags, ilk, file, line)); } break; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
