diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2007-04-19 20:29:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-25 22:26:28 -0700 |
| commit | 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 (patch) | |
| tree | 5a267e40f9b94014be38dad5de0a52b6628834e0 /drivers/atm | |
| parent | be8bd86321fa7f06359d866ef61fb4d2f3e9dce9 (diff) | |
| download | lwn-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.tar.gz lwn-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.zip | |
[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>
Diffstat (limited to 'drivers/atm')
| -rw-r--r-- | drivers/atm/he.c | 4 | ||||
| -rw-r--r-- | drivers/atm/idt77252.c | 3 | ||||
| -rw-r--r-- | drivers/atm/nicstar.c | 10 |
3 files changed, 10 insertions, 7 deletions
diff --git a/drivers/atm/he.c b/drivers/atm/he.c index 8510026b690a..d33aba6864c2 100644 --- a/drivers/atm/he.c +++ b/drivers/atm/he.c @@ -1901,13 +1901,13 @@ he_service_rbrq(struct he_dev *he_dev, int group) case ATM_AAL0: /* 2.10.1.5 raw cell receive */ skb->len = ATM_AAL0_SDU; - skb->tail = skb->data + skb->len; + skb_set_tail_pointer(skb, skb->len); break; case ATM_AAL5: /* 2.10.1.2 aal5 receive */ skb->len = AAL5_LEN(skb->data, he_vcc->pdu_len); - skb->tail = skb->data + skb->len; + skb_set_tail_pointer(skb, skb->len); #ifdef USE_CHECKSUM_HW if (vcc->vpi == 0 && vcc->vci >= ATM_NOT_RSV_VCI) { skb->ip_summed = CHECKSUM_COMPLETE; diff --git a/drivers/atm/idt77252.c b/drivers/atm/idt77252.c index b4b80140c398..1e49799cd6cf 100644 --- a/drivers/atm/idt77252.c +++ b/drivers/atm/idt77252.c @@ -1816,7 +1816,8 @@ push_rx_skb(struct idt77252_dev *card, struct sk_buff *skb, int queue) u32 handle; u32 addr; - skb->data = skb->tail = skb->head; + skb->data = skb->head; + skb_reset_tail_pointer(skb); skb->len = 0; skb_reserve(skb, 16); diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c index aab9b3733d52..26f4b7033494 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -2208,7 +2208,7 @@ static void dequeue_rx(ns_dev *card, ns_rsqe *rsqe) if (i == 1 && ns_rsqe_eopdu(rsqe)) *((u32 *) sb->data) |= 0x00000002; skb_put(sb, NS_AAL0_HEADER); - memcpy(sb->tail, cell, ATM_CELL_PAYLOAD); + memcpy(skb_tail_pointer(sb), cell, ATM_CELL_PAYLOAD); skb_put(sb, ATM_CELL_PAYLOAD); ATM_SKB(sb)->vcc = vcc; __net_timestamp(sb); @@ -2252,7 +2252,8 @@ static void dequeue_rx(ns_dev *card, ns_rsqe *rsqe) vc->rx_iov = iovb; NS_SKB(iovb)->iovcnt = 0; iovb->len = 0; - iovb->tail = iovb->data = iovb->head; + iovb->data = iovb->head; + skb_reset_tail_pointer(iovb); NS_SKB(iovb)->vcc = vcc; /* IMPORTANT: a pointer to the sk_buff containing the small or large buffer is stored as iovec base, NOT a pointer to the @@ -2265,7 +2266,8 @@ static void dequeue_rx(ns_dev *card, ns_rsqe *rsqe) recycle_iovec_rx_bufs(card, (struct iovec *) iovb->data, NS_MAX_IOVECS); NS_SKB(iovb)->iovcnt = 0; iovb->len = 0; - iovb->tail = iovb->data = iovb->head; + iovb->data = iovb->head; + skb_reset_tail_pointer(iovb); NS_SKB(iovb)->vcc = vcc; } iov = &((struct iovec *) iovb->data)[NS_SKB(iovb)->iovcnt++]; @@ -2489,7 +2491,7 @@ static void dequeue_rx(ns_dev *card, ns_rsqe *rsqe) { lb = (struct sk_buff *) iov->iov_base; tocopy = min_t(int, remaining, iov->iov_len); - memcpy(hb->tail, lb->data, tocopy); + memcpy(skb_tail_pointer(hb), lb->data, tocopy); skb_put(hb, tocopy); iov++; remaining -= tocopy; |