Ok, how about this. If the simple form of objcache_create is used
we install simple_objsize and allow M_ZERO. Otherwise we panic if
M_ZERO is specified.
I let the second layer case fall through... if the allocator happens
to be malloc, then M_ZERO will work. If it doesn't, then the problem
will be caught later on when the first layer has cached objects and
the caller tries to get a new object. Not perfect but it should catch
any problems.
-Matt
Index: kern_objcache.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_objcache.c,v
retrieving revision 1.12
diff -u -r1.12 kern_objcache.c
--- kern_objcache.c 20 Nov 2006 22:19:54 -0000 1.12
+++ kern_objcache.c 29 Nov 2006 23:33:00 -0000
@@ -129,6 +129,7 @@
objcache_alloc_fn *alloc;
objcache_free_fn *free;
void *allocator_args;
+ size_t simple_objsize;
SLIST_ENTRY(objcache) oc_next;
@@ -228,6 +229,12 @@
null_ctor, null_dtor, NULL,
objcache_malloc_alloc, objcache_malloc_free,
margs);
+
+ /*
+ * This indicates that we are a simple objcache and allows
+ * objcache_get() calls with M_ZERO.
+ */
+ oc->simple_objsize = objsize;
return (oc);
}
@@ -264,7 +271,14 @@
loadedmag = cpucache->loaded_magazine;
if (MAGAZINE_NOTEMPTY(loadedmag)) {
obj = loadedmag->objects[--loadedmag->rounds];
+done:
crit_exit();
+ if (ocflags & M_ZERO) {
+ if (oc->simple_objsize)
+ bzero(obj, oc->simple_objsize);
+ else
+ panic("objcache_get(): M_ZERO illegal here");
+ }
return (obj);
}
@@ -275,8 +289,7 @@
swap(cpucache->loaded_magazine, cpucache->previous_magazine);
loadedmag = cpucache->loaded_magazine;
obj = loadedmag->objects[--loadedmag->rounds];
- crit_exit();
- return (obj);
+ goto done;
}
/*
@@ -284,6 +297,8 @@
* move one of the empty ones to the depot.
*
* Obtain the depot spinlock.
+ *
+ * NOTE: Beyond this point, M_ZERO is handled via oc->alloc()
*/
depot = &oc->depot[myclusterid];
spin_lock_wr(&depot->spin);
