[SK_BUFF]: Convert skb->tail to sk_buff_data_t
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index ec63b0e..4d8f282 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -335,15 +335,15 @@
sarb = instance->cached_vcc->sarb;
- if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
+ if (skb_tail_pointer(sarb) + ATM_CELL_PAYLOAD > sarb->end) {
atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
__func__, sarb->len, vcc);
/* discard cells already received */
skb_trim(sarb, 0);
- UDSL_ASSERT(sarb->tail + ATM_CELL_PAYLOAD <= sarb->end);
+ UDSL_ASSERT(skb_tail_pointer(sarb) + ATM_CELL_PAYLOAD <= sarb->end);
}
- memcpy(sarb->tail, source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
+ memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
__skb_put(sarb, ATM_CELL_PAYLOAD);
if (pti & 1) {
@@ -370,7 +370,7 @@
goto out;
}
- if (crc32_be(~0, sarb->tail - pdu_length, pdu_length) != 0xc704dd7b) {
+ if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
__func__, vcc);
atomic_inc(&vcc->stats->rx_err);
@@ -396,7 +396,7 @@
goto out; /* atm_charge increments rx_drop */
}
- memcpy(skb->data, sarb->tail - pdu_length, length);
+ memcpy(skb->data, skb_tail_pointer(sarb) - pdu_length, length);
__skb_put(skb, length);
vdbg("%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
diff --git a/drivers/usb/net/asix.c b/drivers/usb/net/asix.c
index 5808ea0..f56e2da 100644
--- a/drivers/usb/net/asix.c
+++ b/drivers/usb/net/asix.c
@@ -298,7 +298,7 @@
if (ax_skb) {
ax_skb->len = size;
ax_skb->data = packet;
- ax_skb->tail = packet + size;
+ skb_set_tail_pointer(ax_skb, size);
usbnet_skb_return(dev, ax_skb);
} else {
return 0;
@@ -338,7 +338,7 @@
&& ((headroom + tailroom) >= (4 + padlen))) {
if ((headroom < 4) || (tailroom < padlen)) {
skb->data = memmove(skb->head + 4, skb->data, skb->len);
- skb->tail = skb->data + skb->len;
+ skb_set_tail_pointer(skb, skb->len);
}
} else {
struct sk_buff *skb2;
@@ -356,7 +356,7 @@
if ((skb->len % 512) == 0) {
cpu_to_le32s(&padbytes);
- memcpy( skb->tail, &padbytes, sizeof(padbytes));
+ memcpy(skb_tail_pointer(skb), &padbytes, sizeof(padbytes));
skb_put(skb, sizeof(padbytes));
}
return skb;
diff --git a/drivers/usb/net/gl620a.c b/drivers/usb/net/gl620a.c
index d257a8e..031cf5c 100644
--- a/drivers/usb/net/gl620a.c
+++ b/drivers/usb/net/gl620a.c
@@ -157,7 +157,7 @@
if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
skb->data = memmove(skb->head + (4 + 4*1),
skb->data, skb->len);
- skb->tail = skb->data + skb->len;
+ skb_set_tail_pointer(skb, skb->len);
}
} else {
struct sk_buff *skb2;
diff --git a/drivers/usb/net/net1080.c b/drivers/usb/net/net1080.c
index ccebfde..19bf8da 100644
--- a/drivers/usb/net/net1080.c
+++ b/drivers/usb/net/net1080.c
@@ -520,7 +520,7 @@
skb->data = memmove(skb->head
+ sizeof (struct nc_header),
skb->data, skb->len);
- skb->tail = skb->data + len;
+ skb_set_tail_pointer(skb, len);
goto encapsulate;
}
}
diff --git a/drivers/usb/net/rndis_host.c b/drivers/usb/net/rndis_host.c
index 39a21c7..1d36772 100644
--- a/drivers/usb/net/rndis_host.c
+++ b/drivers/usb/net/rndis_host.c
@@ -588,7 +588,7 @@
if (likely((sizeof *hdr) <= room)) {
skb->data = memmove(skb->head + sizeof *hdr,
skb->data, len);
- skb->tail = skb->data + len;
+ skb_set_tail_pointer(skb, len);
goto fill;
}
}