svn commit: r283310 - in stable/10/sys: kern vm

[Konstantin Belousov]

Author: kib
Date: Sat May 23 09:14:29 2015
New Revision: 283310
URL: https://svnweb.freebsd.org/changeset/base/283310

Log:
  MFC r282690:
  Call uma_reclaim() from the additional pagedaemon thread to reclaim kmem
  arena address space.

Modified:
  stable/10/sys/kern/kern_malloc.c
  stable/10/sys/vm/uma.h
  stable/10/sys/vm/uma_core.c
  stable/10/sys/vm/vm_pageout.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/kern_malloc.c
==============================================================================
--- stable/10/sys/kern/kern_malloc.c	Sat May 23 08:02:54 2015	(r283309)
+++ stable/10/sys/kern/kern_malloc.c	Sat May 23 09:14:29 2015	(r283310)
@@ -667,13 +667,15 @@ reallocf(void *addr, unsigned long size,
 }
 
 /*
- * Wake the page daemon when we exhaust KVA.  It will call the lowmem handler
- * and uma_reclaim() callbacks in a context that is safe.
+ * Wake the uma reclamation pagedaemon thread when we exhaust KVA.  It
+ * will call the lowmem handler and uma_reclaim() callbacks in a
+ * context that is safe.
  */
 static void
 kmem_reclaim(vmem_t *vm, int flags)
 {
 
+	uma_reclaim_wakeup();
 	pagedaemon_wakeup();
 }
 

Modified: stable/10/sys/vm/uma.h
==============================================================================
--- stable/10/sys/vm/uma.h	Sat May 23 08:02:54 2015	(r283309)
+++ stable/10/sys/vm/uma.h	Sat May 23 09:14:29 2015	(r283310)
@@ -689,4 +689,7 @@ struct uma_percpu_stat {
 	uint64_t	_ups_reserved[5];	/* Reserved. */
 };
 
+void uma_reclaim_wakeup(void);
+void uma_reclaim_worker(void *);
+
 #endif	/* _VM_UMA_H_ */

Modified: stable/10/sys/vm/uma_core.c
==============================================================================
--- stable/10/sys/vm/uma_core.c	Sat May 23 08:02:54 2015	(r283309)
+++ stable/10/sys/vm/uma_core.c	Sat May 23 09:14:29 2015	(r283310)
@@ -3192,16 +3192,17 @@ uma_find_refcnt(uma_zone_t zone, void *i
 }
 
 /* See uma.h */
-void
-uma_reclaim(void)
+static void
+uma_reclaim_locked(bool kmem_danger)
 {
+
 #ifdef UMA_DEBUG
 	printf("UMA: vm asked us to release pages!\n");
 #endif
-	sx_xlock(&uma_drain_lock);
+	sx_assert(&uma_drain_lock, SA_XLOCKED);
 	bucket_enable();
 	zone_foreach(zone_drain);
-	if (vm_page_count_min()) {
+	if (vm_page_count_min() || kmem_danger) {
 		cache_drain_safe(NULL);
 		zone_foreach(zone_drain);
 	}
@@ -3213,9 +3214,42 @@ uma_reclaim(void)
 	zone_drain(slabzone);
 	zone_drain(slabrefzone);
 	bucket_zone_drain();
+}
+
+void
+uma_reclaim(void)
+{
+
+	sx_xlock(&uma_drain_lock);
+	uma_reclaim_locked(false);
 	sx_xunlock(&uma_drain_lock);
 }
 
+static int uma_reclaim_needed;
+
+void
+uma_reclaim_wakeup(void)
+{
+
+	uma_reclaim_needed = 1;
+	wakeup(&uma_reclaim_needed);
+}
+
+void
+uma_reclaim_worker(void *arg __unused)
+{
+
+	sx_xlock(&uma_drain_lock);
+	for (;;) {
+		sx_sleep(&uma_reclaim_needed, &uma_drain_lock, PVM,
+		    "umarcl", 0);
+		if (uma_reclaim_needed) {
+			uma_reclaim_needed = 0;
+			uma_reclaim_locked(true);
+		}
+	}
+}
+
 /* See uma.h */
 int
 uma_zone_exhausted(uma_zone_t zone)

Modified: stable/10/sys/vm/vm_pageout.c
==============================================================================
--- stable/10/sys/vm/vm_pageout.c	Sat May 23 08:02:54 2015	(r283309)
+++ stable/10/sys/vm/vm_pageout.c	Sat May 23 09:14:29 2015	(r283310)
@@ -1726,8 +1726,9 @@ vm_pageout_init(void)
 static void
 vm_pageout(void)
 {
+	int error;
 #if MAXMEMDOM > 1
-	int error, i;
+	int i;
 #endif
 
 	swap_pager_swap_init();
@@ -1741,6 +1742,10 @@ vm_pageout(void)
 		}
 	}
 #endif
+	error = kthread_add(uma_reclaim_worker, NULL, curproc, NULL,
+	    0, 0, "uma");
+	if (error != 0)
+		panic("starting uma_reclaim helper, error %d\n", error);
 	vm_pageout_worker((void *)(uintptr_t)0);
 }