transferlockers() is a very dangerous and hack-ish function as waiters

should never be moved by one lock to another.
As, luckily, nothing in our tree is using it, axe the function.

This breaks lockmgr KPI, so interested, third-party modules should update
their source code with appropriate replacement.

Ok'ed by: ups, rwatson
MFC after: 3 days

1 files changed, 0 insertions, 28 deletions

diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c
index 6a5f213..b06e17e 100644
--- a/sys/kern/kern_lock.c
+++ b/sys/kern/kern_lock.c
@@ -506,34 +506,6 @@ acquiredrain(struct lock *lkp, int extflags) {
 }
 
 /*
- * Transfer any waiting processes from one lock to another.
- */
-void
-transferlockers(from, to)
-	struct lock *from;
-	struct lock *to;
-{
-
-	KASSERT(from != to, ("lock transfer to self"));
-	KASSERT((from->lk_flags&LK_WAITDRAIN) == 0, ("transfer draining lock"));
-
-	mtx_lock(from->lk_interlock);
-	if (from->lk_waitcount == 0) {
-		mtx_unlock(from->lk_interlock);
-		return;
-	}
-	from->lk_newlock = to;
-	wakeup((void *)from);
-	msleep(&from->lk_newlock, from->lk_interlock, from->lk_prio,
-	    "lkxfer", 0);
-	from->lk_newlock = NULL;
-	from->lk_flags &= ~(LK_WANT_EXCL | LK_WANT_UPGRADE);
-	KASSERT(from->lk_waitcount == 0, ("active lock"));
-	mtx_unlock(from->lk_interlock);
-}
-
-
-/*
  * Initialize a lock; required before use.
  */
 void