[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>
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committed by
David S. Miller

parent
be8bd86321
commit
27a884dc3c
@@ -133,8 +133,8 @@ int ircomm_param_request(struct ircomm_tty_cb *self, __u8 pi, int flush)
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* Inserting is a little bit tricky since we don't know how much
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* room we will need. But this should hopefully work OK
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*/
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count = irda_param_insert(self, pi, skb->tail, skb_tailroom(skb),
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&ircomm_param_info);
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count = irda_param_insert(self, pi, skb_tail_pointer(skb),
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skb_tailroom(skb), &ircomm_param_info);
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if (count < 0) {
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IRDA_WARNING("%s(), no room for parameter!\n", __FUNCTION__);
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spin_unlock_irqrestore(&self->spinlock, flags);
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@@ -1039,7 +1039,7 @@ static int __irlan_insert_param(struct sk_buff *skb, char *param, int type,
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}
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/* Insert at end of sk-buffer */
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frame = skb->tail;
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frame = skb_tail_pointer(skb);
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/* Make space for data */
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if (skb_tailroom(skb) < (param_len+value_len+3)) {
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@@ -469,49 +469,49 @@ int irlap_insert_qos_negotiation_params(struct irlap_cb *self,
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int ret;
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/* Insert data rate */
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ret = irda_param_insert(self, PI_BAUD_RATE, skb->tail,
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ret = irda_param_insert(self, PI_BAUD_RATE, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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skb_put(skb, ret);
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/* Insert max turnaround time */
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ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb->tail,
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ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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skb_put(skb, ret);
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/* Insert data size */
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ret = irda_param_insert(self, PI_DATA_SIZE, skb->tail,
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ret = irda_param_insert(self, PI_DATA_SIZE, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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skb_put(skb, ret);
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/* Insert window size */
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ret = irda_param_insert(self, PI_WINDOW_SIZE, skb->tail,
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ret = irda_param_insert(self, PI_WINDOW_SIZE, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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skb_put(skb, ret);
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/* Insert additional BOFs */
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ret = irda_param_insert(self, PI_ADD_BOFS, skb->tail,
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ret = irda_param_insert(self, PI_ADD_BOFS, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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skb_put(skb, ret);
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/* Insert minimum turnaround time */
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ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb->tail,
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ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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skb_put(skb, ret);
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/* Insert link disconnect/threshold time */
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ret = irda_param_insert(self, PI_LINK_DISC, skb->tail,
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ret = irda_param_insert(self, PI_LINK_DISC, skb_tail_pointer(skb),
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skb_tailroom(skb), &irlap_param_info);
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if (ret < 0)
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return ret;
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