[PATCH 2/2] kernel: Replace {,LW}P{HOLD,RELE} to use refcount APIs

[YONETANI Tomokazu <y0netan1@xxxxxxxxxxxxxxxx>]

---
 sys/kern/kern_exit.c                   |   14 +++++++-------
 sys/kern/kern_proc.c                   |    8 ++------
 sys/platform/pc32/i386/pmap.c          |    3 ++-
 sys/platform/pc64/x86_64/pmap.c        |    3 ++-
 sys/platform/vkernel/platform/pmap.c   |    3 ++-
 sys/platform/vkernel64/platform/pmap.c |    3 ++-
 sys/sys/proc.h                         |   11 +++++++----
 7 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index dda3a3e..0d35a37 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -619,8 +619,7 @@ lwp_exit(int masterexit)
 	 * Nobody actually wakes us when the lock
 	 * count reaches zero, so just wait one tick.
 	 */
-	while (lp->lwp_lock > 0)
-		tsleep(lp, 0, "lwpexit", 1);
+	LWPLOCKWAIT(lp, "lwpexit", 1);
 
 	/* Hand down resource usage to our proc */
 	ruadd(&p->p_ru, &lp->lwp_ru);
@@ -690,8 +689,7 @@ lwp_wait(struct lwp *lp)
 
 	KKASSERT(lwkt_preempted_proc() != lp);
 
-	while (lp->lwp_lock > 0)
-		tsleep(lp, 0, "lwpwait1", 1);
+	LWPLOCKWAIT(lp, "lwpwait1", 1);
 
 	lwkt_wait_free(td);
 
@@ -867,8 +865,7 @@ loop:
 			 * put a hold on the process for short periods of
 			 * time.
 			 */
-			while (p->p_lock)
-				tsleep(p, 0, "reap3", hz);
+			PLOCKWAIT(p, "reap3", hz);
 
 			/* Take care of our return values. */
 			*res = p->p_pid;
@@ -898,7 +895,10 @@ loop:
 			 * inconsistent state for processes running down
 			 * the zombie list.
 			 */
-			KKASSERT(p->p_lock == 0);
+			if (p->p_lock) {
+				kprintf("%s: pid %d is still held (%x)\n",
+					__func__, p->p_pid, p->p_lock);
+			}
 			proc_remove_zombie(p);
 			leavepgrp(p);
 
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index cb067f0..6d760e2 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -638,9 +638,7 @@ void
 proc_move_allproc_zombie(struct proc *p)
 {
 	lwkt_gettoken(&proc_token);
-	while (p->p_lock) {
-		tsleep(p, 0, "reap1", hz / 10);
-	}
+	PLOCKWAIT(p, "reap1", hz / 10);
 	LIST_REMOVE(p, p_list);
 	LIST_INSERT_HEAD(&zombproc, p, p_list);
 	LIST_REMOVE(p, p_hash);
@@ -660,9 +658,7 @@ void
 proc_remove_zombie(struct proc *p)
 {
 	lwkt_gettoken(&proc_token);
-	while (p->p_lock) {
-		tsleep(p, 0, "reap1", hz / 10);
-	}
+	PLOCKWAIT(p, "reap1", hz / 10);
 	LIST_REMOVE(p, p_list); /* off zombproc */
 	LIST_REMOVE(p, p_sibling);
 	lwkt_reltoken(&proc_token);
diff --git a/sys/platform/pc32/i386/pmap.c b/sys/platform/pc32/i386/pmap.c
index 25816c5..8936a01 100644
--- a/sys/platform/pc32/i386/pmap.c
+++ b/sys/platform/pc32/i386/pmap.c
@@ -1020,7 +1020,8 @@ pmap_init_proc(struct proc *p)
 void
 pmap_dispose_proc(struct proc *p)
 {
-	KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p));
+	KASSERT(p->p_lock == 0,
+		("attempt to dispose referenced or waited for proc! %p", p));
 }
 
 /***************************************************
diff --git a/sys/platform/pc64/x86_64/pmap.c b/sys/platform/pc64/x86_64/pmap.c
index 3ab87c9..b119773 100644
--- a/sys/platform/pc64/x86_64/pmap.c
+++ b/sys/platform/pc64/x86_64/pmap.c
@@ -1151,7 +1151,8 @@ pmap_init_proc(struct proc *p)
 void
 pmap_dispose_proc(struct proc *p)
 {
-	KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p));
+	KASSERT(p->p_lock == 0,
+		("attempt to dispose referenced or waited for proc! %p", p));
 }
 
 /***************************************************
diff --git a/sys/platform/vkernel/platform/pmap.c b/sys/platform/vkernel/platform/pmap.c
index 125fcdc..6c03106 100644
--- a/sys/platform/vkernel/platform/pmap.c
+++ b/sys/platform/vkernel/platform/pmap.c
@@ -888,7 +888,8 @@ pmap_init_proc(struct proc *p)
 void
 pmap_dispose_proc(struct proc *p)
 {
-	KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p));
+	KASSERT(p->p_lock == 0,
+		("attempt to dispose referenced or waited for proc! %p", p));
 }
 
 /*
diff --git a/sys/platform/vkernel64/platform/pmap.c b/sys/platform/vkernel64/platform/pmap.c
index 246d36a..ed3f6a3 100644
--- a/sys/platform/vkernel64/platform/pmap.c
+++ b/sys/platform/vkernel64/platform/pmap.c
@@ -905,7 +905,8 @@ pmap_init_proc(struct proc *p)
 void
 pmap_dispose_proc(struct proc *p)
 {
-	KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p));
+	KASSERT(p->p_lock == 0,
+		("attempt to dispose referenced or waited for proc! %p", p));
 }
 
 /***************************************************
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index be6ad41..29b2568 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -56,6 +56,7 @@
 #include <sys/rtprio.h>			/* For struct rtprio. */
 #include <sys/signal.h>
 #include <sys/lock.h>
+#include <sys/refcount.h>
 #ifndef _KERNEL
 #include <sys/time.h>			/* For structs itimerval, timeval. */
 #endif
@@ -444,16 +445,18 @@ extern void stopevent(struct proc*, unsigned int, unsigned int);
  *
  * MPSAFE
  */
-#define PHOLD(p)	atomic_add_int(&(p)->p_lock, 1)
-#define PRELE(p)	atomic_add_int(&(p)->p_lock, -1)
+#define PHOLD(p)	refcount_acquire(&(p)->p_lock)
+#define PRELE(p)	refcount_release_wakeup(&(p)->p_lock)
+#define PLOCKWAIT(p, wmesg, timo)	refcount_wait(&(p)->p_lock, wmesg)
 
 /*
  * Hold lwp in memory, don't destruct, normally for ptrace/procfs work
  * atomic ops because they can occur from an IPI.
  * MPSAFE
  */
-#define LWPHOLD(lp)	atomic_add_int(&(lp)->lwp_lock, 1)
-#define LWPRELE(lp)	atomic_add_int(&(lp)->lwp_lock, -1)
+#define LWPHOLD(lp)	refcount_acquire(&(lp)->lwp_lock)
+#define LWPRELE(lp)	refcount_release_wakeup(&(lp)->lwp_lock)
+#define LWPLOCKWAIT(lp, wmesg, timo)	refcount_wait(&(lp)->lwp_lock, wmesg)
 
 #define	PIDHASH(pid)	(&pidhashtbl[(pid) & pidhash])
 extern LIST_HEAD(pidhashhead, proc) *pidhashtbl;
-- 
1.7.3.2


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