Compile tested only!!!
Fix optimization of netdev_priv() lost by the addition of multiqueue.
Move the variable size subqueues to after the constant size priv area.
When putting back the old netdev_priv() code, I tried to make it
clearer by using roundup() and ALIGN() macros.
--- a/include/linux/netdevice.h 2007-08-17 12:08:51.000000000 -0400
+++ b/include/linux/netdevice.h 2007-08-17 12:48:03.000000000 -0400
@@ -575,16 +575,15 @@ struct net_device
/* The TX queue control structures */
unsigned int egress_subqueue_count;
- struct net_device_subqueue egress_subqueue[1];
+ struct net_device_subqueue *egress_subqueue;
};
#define to_net_dev(d) container_of(d, struct net_device, dev)
#define NETDEV_ALIGN 32
-#define NETDEV_ALIGN_CONST (NETDEV_ALIGN - 1)
static inline void *netdev_priv(const struct net_device *dev)
{
- return dev->priv;
+ return (void *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
}
#define SET_MODULE_OWNER(dev) do { } while (0)
--- a/net/core/dev.c 2007-08-17 09:02:57.000000000 -0400
+++ b/net/core/dev.c 2007-08-17 12:48:30.000000000 -0400
@@ -3706,7 +3706,22 @@ EXPORT_SYMBOL(dev_get_stats);
* @queue_count: the number of subqueues to allocate
*
* Allocates a struct net_device with private data area for driver use
- * and performs basic initialization. Also allocates subquue structs
+ * and performs basic initialization.
+ *
+ * Layout:
+ * allocation->+------------+
+ * | (pad) | dev->padded
+ * dev -->+------------+ -- (32 byte boundary)
+ * | net_device |
+ * netdev_priv(dev) -->+------------+ -- (32 byte boundary)
+ * | device |
+ * | private |
+ * | |
+ * dev->egress_subqueue -->+------------+ -- (32 byte boundary)
+ * | Tx queue(s)|
+ * +------------+
+ *
+ * Also allocates subqueue structs
* for each queue on the device at the end of the netdevice.
*/
struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
@@ -3719,10 +3734,9 @@ struct net_device *alloc_netdev_mq(int s
BUG_ON(strlen(name) >= sizeof(dev->name));
/* ensure 32-byte alignment of both the device and private area */
- alloc_size = (sizeof(*dev) + NETDEV_ALIGN_CONST +
- (sizeof(struct net_device_subqueue) * (queue_count - 1))) &
- ~NETDEV_ALIGN_CONST;
- alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;
+ alloc_size = roundup(sizeof(*dev), NETDEV_ALIGN);
+ alloc_size += roundup(sizeof_priv, NETDEV_ALIGN);
+ alloc_size += sizeof(struct net_device_subqueue) * queue_count;
p = kzalloc(alloc_size, GFP_KERNEL);
if (!p) {
@@ -3730,19 +3744,20 @@ struct net_device *alloc_netdev_mq(int s
return NULL;
}
- dev = (struct net_device *)
- (((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
+ /* Pad so that network device is on cache line boundary */
+ dev = (struct net_device *) ALIGN((unsigned long) p, NETDEV_ALIGN);
dev->padded = (char *)dev - (char *)p;
- if (sizeof_priv) {
- dev->priv = ((char *)dev +
- ((sizeof(struct net_device) +
- (sizeof(struct net_device_subqueue) *
- (queue_count - 1)) + NETDEV_ALIGN_CONST)
- & ~NETDEV_ALIGN_CONST));
- }
+ if (sizeof_priv)
+ dev->priv = netdev_priv(dev);
+ /* Put subqueue(s) which are variable size after fix sized priv area */
dev->egress_subqueue_count = queue_count;
+ dev->egress_subqueue = ALIGN((unsigned long)(netdev_priv(dev) +
sizeof_priv),
+ NETDEV_ALIGN);
+
+ pr_debug("alloc_netdev_mq: p=%p dev=%p priv=%p q=%p\n",
+ p, dev, dev->priv, dev->egress_subqueue);
setup(dev);
strcpy(dev->name, name);
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
