malloc/free(9) no longer require Giant. Use the malloc_mtx to protect the

mallochash.  Mallochash is going to go away as soon as I introduce the
kfree/kmalloc api and partially overhaul the malloc wrapper.  This can't happen
until all users of the malloc api that expect memory to be aligned on the size
of the allocation are fixed.

1 files changed, 17 insertions, 8 deletions

diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index 00b489b..672c71f 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -471,10 +471,13 @@ bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
 		 * hold them.  This will go away when free() gets a size passed
 		 * to it.
 		 */
-		if (mzone)
+		if (mzone) {
+			mtx_lock(&malloc_mtx);
 			slab = hash_sfind(mallochash,
 			    (u_int8_t *)((unsigned long)item &
 			   (~UMA_SLAB_MASK)));
+			mtx_unlock(&malloc_mtx);
+		}
 		uma_zfree_internal(zone, item, slab, 1);
 	}
 }
@@ -616,17 +619,18 @@ zone_drain(uma_zone_t zone)
 				    zone->uz_size);
 		flags = slab->us_flags;
 		mem = slab->us_data;
+		if (zone->uz_flags & UMA_ZFLAG_MALLOC) {
+			mtx_lock(&malloc_mtx);
+			UMA_HASH_REMOVE(mallochash, slab, slab->us_data);
+			mtx_unlock(&malloc_mtx);
+		}
 		if (zone->uz_flags & UMA_ZFLAG_OFFPAGE) {
-			if (zone->uz_flags & UMA_ZFLAG_MALLOC) {
-				UMA_HASH_REMOVE(mallochash,
-				    slab, slab->us_data); 
-			} else {
+			if (!(zone->uz_flags & UMA_ZFLAG_MALLOC)) {
 				UMA_HASH_REMOVE(&zone->uz_hash,
 				    slab, slab->us_data);
 			}
 			uma_zfree_internal(slabzone, slab, NULL, 0);
-		} else if (zone->uz_flags & UMA_ZFLAG_MALLOC)
-			UMA_HASH_REMOVE(mallochash, slab, slab->us_data);
+		}
 #ifdef UMA_DEBUG
 		printf("%s: Returning %d bytes.\n",
 		    zone->uz_name, UMA_SLAB_SIZE * zone->uz_ppera);
@@ -714,8 +718,9 @@ slab_zalloc(uma_zone_t zone, int wait)
 		printf("Inserting %p into malloc hash from slab %p\n",
 		    mem, slab);
 #endif
-		/* XXX Yikes! No lock on the malloc hash! */
+		mtx_lock(&malloc_mtx);
 		UMA_HASH_INSERT(mallochash, slab, mem);
+		mtx_unlock(&malloc_mtx);
 	}
 
 	slab->us_zone = zone;
@@ -1958,7 +1963,9 @@ uma_large_malloc(int size, int wait)
 		slab->us_data = mem;
 		slab->us_flags = flags | UMA_SLAB_MALLOC;
 		slab->us_size = size;
+		mtx_lock(&malloc_mtx);
 		UMA_HASH_INSERT(mallochash, slab, mem);
+		mtx_unlock(&malloc_mtx);
 	} else {
 		uma_zfree_internal(slabzone, slab, NULL, 0);
 	}
@@ -1970,7 +1977,9 @@ uma_large_malloc(int size, int wait)
 void
 uma_large_free(uma_slab_t slab)
 {
+	mtx_lock(&malloc_mtx);
 	UMA_HASH_REMOVE(mallochash, slab, slab->us_data);
+	mtx_unlock(&malloc_mtx);
 	page_free(slab->us_data, slab->us_size, slab->us_flags);
 	uma_zfree_internal(slabzone, slab, NULL, 0);
 }