* Add a "how" argument to uma_zone constructors and initialization functions

  so that they know whether the allocation is supposed to be able to sleep
  or not.
* Allow uma_zone constructors and initialation functions to return either
  success or error.  Almost all of the ones in the tree currently return
  success unconditionally, but mbuf is a notable exception: the packet
  zone constructor wants to be able to fail if it cannot suballocate an
  mbuf cluster, and the mbuf allocators want to be able to fail in general
  in a MAC kernel if the MAC mbuf initializer fails.  This fixes the
  panics people are seeing when they run out of memory for mbuf clusters.
* Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing
  the default.

Both bmilekic and jeff have reviewed the changes made to make failable
zone allocations work.

1 files changed, 18 insertions, 18 deletions

diff --git a/sys/vm/uma_dbg.c b/sys/vm/uma_dbg.c
index 0f845cf..cbf164a 100644
--- a/sys/vm/uma_dbg.c
+++ b/sys/vm/uma_dbg.c
@@ -51,13 +51,14 @@ __FBSDID("$FreeBSD$");
 static const u_int32_t uma_junk = 0xdeadc0de;
 
 /*
- * Checks an item to make sure it hasn't been overwritten since freed.
+ * Checks an item to make sure it hasn't been overwritten since it was freed,
+ * prior to subsequent reallocation.
  *
  * Complies with standard ctor arg/return
  *
  */
-void
-trash_ctor(void *mem, int size, void *arg)
+int
+trash_ctor(void *mem, int size, void *arg, int flags)
 {
 	int cnt;
 	u_int32_t *p;
@@ -68,6 +69,7 @@ trash_ctor(void *mem, int size, void *arg)
 		if (*p != uma_junk)
 			panic("Memory modified after free %p(%d) val=%x @ %p\n",
 			    mem, size, *p, p);
+	return (0);
 }
 
 /*
@@ -94,10 +96,11 @@ trash_dtor(void *mem, int size, void *arg)
  * Complies with standard init arg/return
  *
  */
-void
-trash_init(void *mem, int size)
+int
+trash_init(void *mem, int size, int flags)
 {
 	trash_dtor(mem, size, NULL);
+	return (0);
 }
 
 /*
@@ -109,17 +112,11 @@ trash_init(void *mem, int size)
 void
 trash_fini(void *mem, int size)
 {
-	trash_ctor(mem, size, NULL);
+	(void)trash_ctor(mem, size, NULL, 0);
 }
 
-/*
- * Checks an item to make sure it hasn't been overwritten since freed.
- *
- * Complies with standard ctor arg/return
- *
- */
-void
-mtrash_ctor(void *mem, int size, void *arg)
+int
+mtrash_ctor(void *mem, int size, void *arg, int flags)
 {
 	struct malloc_type **ksp;
 	u_int32_t *p = mem;
@@ -137,6 +134,7 @@ mtrash_ctor(void *mem, int size, void *arg)
 			panic("Most recently used by %s\n", (*ksp == NULL)?
 			    "none" : (*ksp)->ks_shortdesc);
 		}
+	return (0);
 }
 
 /*
@@ -164,8 +162,8 @@ mtrash_dtor(void *mem, int size, void *arg)
  * Complies with standard init arg/return
  *
  */
-void
-mtrash_init(void *mem, int size)
+int
+mtrash_init(void *mem, int size, int flags)
 {
 	struct malloc_type **ksp;
 
@@ -174,10 +172,12 @@ mtrash_init(void *mem, int size)
 	ksp = (struct malloc_type **)mem;
 	ksp += (size / sizeof(struct malloc_type *)) - 1;
 	*ksp = NULL;
+	return (0);
 }
 
 /*
- * Checks an item to make sure it hasn't been overwritten since it was freed.
+ * Checks an item to make sure it hasn't been overwritten since it was freed,
+ * prior to freeing it back to available memory.
  *
  * Complies with standard fini arg/return
  *
@@ -185,7 +185,7 @@ mtrash_init(void *mem, int size)
 void
 mtrash_fini(void *mem, int size)
 {
-	mtrash_ctor(mem, size, NULL);
+	(void)mtrash_ctor(mem, size, NULL, 0);
 }
 
 static uma_slab_t