[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20070817174909.5e890ad6@freepuppy.rosehill.hemminger.net>
Date: Fri, 17 Aug 2007 17:49:09 -0700
From: Stephen Hemminger <shemminger@...ux-foundation.org>
To: David Miller <davem@...emloft.net>
Cc: netdev@...r.kernel.org
Subject: [RFC] restore netdev_priv optimization (planb)
Fix optimization of netdev_priv() lost by the addition of multiqueue.
Only configurations that define MULITQUEUE need the extra overhead in
netdevice structure and the loss of the netdev_priv optimization.
Signed-off-by: Stephen Hemminger <shemminger@...ux-foundation.org>
--- a/include/linux/netdevice.h 2007-08-17 16:45:39.000000000 -0700
+++ b/include/linux/netdevice.h 2007-08-17 17:31:51.000000000 -0700
@@ -574,17 +574,22 @@ struct net_device
const struct rtnl_link_ops *rtnl_link_ops;
/* The TX queue control structures */
- unsigned int egress_subqueue_count;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+ unsigned short egress_subqueue_count;
struct net_device_subqueue egress_subqueue[1];
+#endif
};
#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)
{
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
return dev->priv;
+#else
+ return (void *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
+#endif
}
#define SET_MODULE_OWNER(dev) do { } while (0)
--- a/net/core/dev.c 2007-08-17 16:45:39.000000000 -0700
+++ b/net/core/dev.c 2007-08-17 17:44:02.000000000 -0700
@@ -3706,7 +3706,7 @@ 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. 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,
@@ -3714,15 +3714,20 @@ struct net_device *alloc_netdev_mq(int s
{
void *p;
struct net_device *dev;
- int alloc_size;
+ size_t dev_size, alloc_size;
BUG_ON(strlen(name) >= sizeof(dev->name));
+#ifndef CONFIG_NETDEVICES_MULTIQUEUE
+ BUG_ON(queue_count > 1);
+#endif
+
/* 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;
+ dev_size = sizeof(*dev)
+ + (queue_count - 1) * sizeof(struct net_device_subqueue);
+
+ alloc_size = roundup(dev_size, NETDEV_ALIGN);
+ alloc_size += sizeof_priv + NETDEV_ALIGN - 1;
p = kzalloc(alloc_size, GFP_KERNEL);
if (!p) {
@@ -3730,19 +3735,17 @@ struct net_device *alloc_netdev_mq(int s
return NULL;
}
- dev = (struct net_device *)
- (((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
+ 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));
- }
-
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
dev->egress_subqueue_count = queue_count;
+ if (sizeof_priv)
+ dev->priv = ALIGN((unsigned long)dev + dev_size, NETDEV_ALIGN);
+#else
+ if (sizeof_priv)
+ dev->priv = netdev_priv(dev);
+#endif
setup(dev);
strcpy(dev->name, name);
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists