objcache: Make sure magazines are cache line aligned

This also makes magazines' size multiple cache line size.

diff --git a/sys/kern/kern_objcache.c b/sys/kern/kern_objcache.c
index ba6dbc9..f96898b 100644 (file)
--- a/sys/kern/kern_objcache.c
+++ b/sys/kern/kern_objcache.c
@@ -59,6 +59,10 @@ struct magazine {
 
 SLIST_HEAD(magazinelist, magazine);
 
+#define MAGAZINE_HDRSIZE       __offsetof(struct magazine, objects[0])
+#define MAGAZINE_CAPACITY_MAX  128
+#define MAGAZINE_CAPACITY_MIN  4
+
 /*
  * per-cluster cache of magazines
  *
@@ -140,19 +144,37 @@ struct objcache {
 
 static struct spinlock objcachelist_spin;
 static LIST_HEAD(objcachelist, objcache) allobjcaches;
+static int magazine_capmin;
+static int magazine_capmax;
 
 static struct magazine *
 mag_alloc(int capacity)
 {
        struct magazine *mag;
+       int size;
+
+       size = __offsetof(struct magazine, objects[capacity]);
+       KASSERT(size > 0 && (size & __VM_CACHELINE_MASK) == 0,
+           ("magazine size is not multiple cache line size"));
 
-       mag = kmalloc(__offsetof(struct magazine, objects[capacity]),
-                       M_OBJMAG, M_INTWAIT | M_ZERO);
+       mag = kmalloc_cachealign(size, M_OBJMAG, M_INTWAIT | M_ZERO);
        mag->capacity = capacity;
        mag->rounds = 0;
        return (mag);
 }
 
+static int
+mag_capacity_align(int mag_capacity)
+{
+       int mag_size;
+
+       mag_size = __VM_CACHELINE_ALIGN(
+           __offsetof(struct magazine, objects[mag_capacity]));
+       mag_capacity = (mag_size - MAGAZINE_HDRSIZE) / sizeof(void *);
+
+       return mag_capacity;
+}
+
 /*
  * Utility routine for objects that don't require any de-construction.
  */
@@ -223,13 +245,13 @@ objcache_create(const char *name, int cluster_limit, int nom_cache,
 
        /*
         * Magazine capacity for 2 active magazines per cpu plus 2
-        * magazines in the depot.  Minimum capacity is 4 objects.
+        * magazines in the depot.
         */
-       mag_capacity = nom_cache / (ncpus + 1) / 2 + 1;
-       if (mag_capacity > 128)
-               mag_capacity = 128;
-       if (mag_capacity < 4)
-               mag_capacity = 4;
+       mag_capacity = mag_capacity_align(nom_cache / (ncpus + 1) / 2 + 1);
+       if (mag_capacity > magazine_capmax)
+               mag_capacity = magazine_capmax;
+       else if (mag_capacity < magazine_capmin)
+               mag_capacity = magazine_capmin;
        depot->magcapacity = mag_capacity;
 
        /*
@@ -972,6 +994,14 @@ static void
 objcache_init(void)
 {
        spin_init(&objcachelist_spin);
+
+       magazine_capmin = mag_capacity_align(MAGAZINE_CAPACITY_MIN);
+       magazine_capmax = mag_capacity_align(MAGAZINE_CAPACITY_MAX);
+       if (bootverbose) {
+               kprintf("objcache: magazine cap [%d, %d]\n",
+                   magazine_capmin, magazine_capmax);
+       }
+
 #if 0
        callout_init_mp(&objcache_callout);
        objcache_rebalance_period = 60 * hz;