Re: [PATCH 3/3] deinline a few large functions in vlan code - v3
From: Denis Vlasenko
Date: Tue Apr 11 2006 - 08:24:33 EST
On Tuesday 11 April 2006 11:36, David S. Miller wrote:
> From: Denis Vlasenko <vda@xxxxxxxxxxxxx>
> Date: Tue, 11 Apr 2006 11:11:12 +0300
>
> > Ok, one last try. Would you like this smallish patch instead?
> > It takes care of those BIG inlines.
>
> You're putting vlan stuff into a net/core/*.c file, that
> is not correct.
This code is _already_ there, duplicated in every driver
of VLAN-capable NIC.
In other words:
if you have just one VLAN-capable NIC driver compiled in,
you have that code in bzImage. If you have ten drivers,
you have that code duplicated ten times.
On my current kernel, I have several dozens NIC drivers
compiled in, because I don't want to mess with modules
on initrd for network boot...
Regarding net/core/*.c. You are right.
The below patch puts this code into net/8021q/if_vlan.c.
Does it look better?
--
vda
diff -urpN linux-2.6.16.org/include/linux/if_vlan.h linux-2.6.16.vlanmini/include/linux/if_vlan.h
--- linux-2.6.16.org/include/linux/if_vlan.h Mon Mar 20 07:53:29 2006
+++ linux-2.6.16.vlanmini/include/linux/if_vlan.h Tue Apr 11 15:08:31 2006
@@ -149,49 +149,9 @@ struct vlan_skb_tx_cookie {
#define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag)
/* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
-static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
+int __vlan_hwaccel_rx(struct sk_buff *skb,
struct vlan_group *grp,
- unsigned short vlan_tag, int polling)
-{
- struct net_device_stats *stats;
-
- skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK];
- if (skb->dev == NULL) {
- dev_kfree_skb_any(skb);
-
- /* Not NET_RX_DROP, this is not being dropped
- * due to congestion.
- */
- return 0;
- }
-
- skb->dev->last_rx = jiffies;
-
- stats = vlan_dev_get_stats(skb->dev);
- stats->rx_packets++;
- stats->rx_bytes += skb->len;
-
- skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
- switch (skb->pkt_type) {
- case PACKET_BROADCAST:
- break;
-
- case PACKET_MULTICAST:
- stats->multicast++;
- break;
-
- case PACKET_OTHERHOST:
- /* Our lower layer thinks this is not local, let's make sure.
- * This allows the VLAN to have a different MAC than the underlying
- * device, and still route correctly.
- */
- if (!memcmp(eth_hdr(skb)->h_dest, skb->dev->dev_addr, ETH_ALEN))
- skb->pkt_type = PACKET_HOST;
- break;
- };
-
- return (polling ? netif_receive_skb(skb) : netif_rx(skb));
-}
+ unsigned short vlan_tag, int polling);
static inline int vlan_hwaccel_rx(struct sk_buff *skb,
struct vlan_group *grp,
@@ -218,43 +178,7 @@ static inline int vlan_hwaccel_receive_s
* Following the skb_unshare() example, in case of error, the calling function
* doesn't have to worry about freeing the original skb.
*/
-static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
-{
- struct vlan_ethhdr *veth;
-
- if (skb_headroom(skb) < VLAN_HLEN) {
- struct sk_buff *sk_tmp = skb;
- skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
- kfree_skb(sk_tmp);
- if (!skb) {
- printk(KERN_ERR "vlan: failed to realloc headroom\n");
- return NULL;
- }
- } else {
- skb = skb_unshare(skb, GFP_ATOMIC);
- if (!skb) {
- printk(KERN_ERR "vlan: failed to unshare skbuff\n");
- return NULL;
- }
- }
-
- veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
-
- /* Move the mac addresses to the beginning of the new header. */
- memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
-
- /* first, the ethernet type */
- veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
-
- /* now, the tag */
- veth->h_vlan_TCI = htons(tag);
-
- skb->protocol = __constant_htons(ETH_P_8021Q);
- skb->mac.raw -= VLAN_HLEN;
- skb->nh.raw -= VLAN_HLEN;
-
- return skb;
-}
+struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag);
/**
* __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
diff -urpN linux-2.6.16.org/net/8021q/Makefile linux-2.6.16.vlanmini/net/8021q/Makefile
--- linux-2.6.16.org/net/8021q/Makefile Mon Mar 20 07:53:29 2006
+++ linux-2.6.16.vlanmini/net/8021q/Makefile Tue Apr 11 15:08:51 2006
@@ -2,6 +2,8 @@
# Makefile for the Linux VLAN layer.
#
+obj-y += if_vlan.o
+
obj-$(CONFIG_VLAN_8021Q) += 8021q.o
8021q-objs := vlan.o vlan_dev.o
diff -urpN linux-2.6.16.org/net/8021q/if_vlan.c linux-2.6.16.vlanmini/net/8021q/if_vlan.c
--- linux-2.6.16.org/net/8021q/if_vlan.c Thu Jan 1 03:00:00 1970
+++ linux-2.6.16.vlanmini/net/8021q/if_vlan.c Tue Apr 11 15:07:09 2006
@@ -0,0 +1,106 @@
+/* 802.1q helpers.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/if_vlan.h>
+
+/* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
+int __vlan_hwaccel_rx(struct sk_buff *skb,
+ struct vlan_group *grp,
+ unsigned short vlan_tag, int polling)
+{
+ struct net_device_stats *stats;
+
+ skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK];
+ if (skb->dev == NULL) {
+ dev_kfree_skb_any(skb);
+
+ /* Not NET_RX_DROP, this is not being dropped
+ * due to congestion.
+ */
+ return 0;
+ }
+
+ skb->dev->last_rx = jiffies;
+
+ stats = vlan_dev_get_stats(skb->dev);
+ stats->rx_packets++;
+ stats->rx_bytes += skb->len;
+
+ skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
+ switch (skb->pkt_type) {
+ case PACKET_BROADCAST:
+ break;
+
+ case PACKET_MULTICAST:
+ stats->multicast++;
+ break;
+
+ case PACKET_OTHERHOST:
+ /* Our lower layer thinks this is not local, let's make sure.
+ * This allows the VLAN to have a different MAC than the underlying
+ * device, and still route correctly.
+ */
+ if (!memcmp(eth_hdr(skb)->h_dest, skb->dev->dev_addr, ETH_ALEN))
+ skb->pkt_type = PACKET_HOST;
+ break;
+ };
+
+ return (polling ? netif_receive_skb(skb) : netif_rx(skb));
+}
+EXPORT_SYMBOL(__vlan_hwaccel_rx);
+
+/**
+ * __vlan_put_tag - regular VLAN tag inserting
+ * @skb: skbuff to tag
+ * @tag: VLAN tag to insert
+ *
+ * Inserts the VLAN tag into @skb as part of the payload
+ * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
+ *
+ * Following the skb_unshare() example, in case of error, the calling function
+ * doesn't have to worry about freeing the original skb.
+ */
+struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
+{
+ struct vlan_ethhdr *veth;
+
+ if (skb_headroom(skb) < VLAN_HLEN) {
+ struct sk_buff *sk_tmp = skb;
+ skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
+ kfree_skb(sk_tmp);
+ if (!skb) {
+ printk(KERN_ERR "vlan: failed to realloc headroom\n");
+ return NULL;
+ }
+ } else {
+ skb = skb_unshare(skb, GFP_ATOMIC);
+ if (!skb) {
+ printk(KERN_ERR "vlan: failed to unshare skbuff\n");
+ return NULL;
+ }
+ }
+
+ veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
+
+ /* Move the mac addresses to the beginning of the new header. */
+ memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
+
+ /* first, the ethernet type */
+ veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
+
+ /* now, the tag */
+ veth->h_vlan_TCI = htons(tag);
+
+ skb->protocol = __constant_htons(ETH_P_8021Q);
+ skb->mac.raw -= VLAN_HLEN;
+ skb->nh.raw -= VLAN_HLEN;
+
+ return skb;
+}
+EXPORT_SYMBOL(__vlan_put_tag);
diff -urpN linux-2.6.16.org/net/Makefile linux-2.6.16.vlanmini/net/Makefile
--- linux-2.6.16.org/net/Makefile Mon Mar 20 07:53:29 2006
+++ linux-2.6.16.vlanmini/net/Makefile Tue Apr 11 15:05:11 2006
@@ -41,7 +41,7 @@ obj-$(CONFIG_RXRPC) += rxrpc/
obj-$(CONFIG_ATM) += atm/
obj-$(CONFIG_DECNET) += decnet/
obj-$(CONFIG_ECONET) += econet/
-obj-$(CONFIG_VLAN_8021Q) += 8021q/
+obj-y += 8021q/
obj-$(CONFIG_IP_DCCP) += dccp/
obj-$(CONFIG_IP_SCTP) += sctp/
obj-$(CONFIG_IEEE80211) += ieee80211/