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| 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/s390/net/ctcmain.c | |
| 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/s390/net/ctcmain.c')
| -rw-r--r-- | drivers/s390/net/ctcmain.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/s390/net/ctcmain.c b/drivers/s390/net/ctcmain.c index 787c01317042..54e3f806cd52 100644 --- a/drivers/s390/net/ctcmain.c +++ b/drivers/s390/net/ctcmain.c @@ -706,7 +706,8 @@ ch_action_txdone(fsm_instance * fi, int event, void *arg) spin_unlock(&ch->collect_lock); return; } - ch->trans_skb->tail = ch->trans_skb->data = ch->trans_skb_data; + ch->trans_skb->data = ch->trans_skb_data; + skb_reset_tail_pointer(ch->trans_skb); ch->trans_skb->len = 0; if (ch->prof.maxmulti < (ch->collect_len + 2)) ch->prof.maxmulti = ch->collect_len + 2; @@ -831,7 +832,8 @@ ch_action_rx(fsm_instance * fi, int event, void *arg) ctc_unpack_skb(ch, skb); } again: - skb->data = skb->tail = ch->trans_skb_data; + skb->data = ch->trans_skb_data; + skb_reset_tail_pointer(skb); skb->len = 0; if (ctc_checkalloc_buffer(ch, 1)) return; @@ -2226,7 +2228,8 @@ transmit_skb(struct channel *ch, struct sk_buff *skb) * IDAL support in CTC is broken, so we have to * care about skb's above 2G ourselves. */ - hi = ((unsigned long) skb->tail + LL_HEADER_LENGTH) >> 31; + hi = ((unsigned long)skb_tail_pointer(skb) + + LL_HEADER_LENGTH) >> 31; if (hi) { nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA); if (!nskb) { @@ -2262,7 +2265,7 @@ transmit_skb(struct channel *ch, struct sk_buff *skb) return -EBUSY; } - ch->trans_skb->tail = ch->trans_skb->data; + skb_reset_tail_pointer(ch->trans_skb); ch->trans_skb->len = 0; ch->ccw[1].count = skb->len; memcpy(skb_put(ch->trans_skb, skb->len), skb->data, |