From: Mitchell Blank Jr <mitch@sfgoth.com>
To: netdev@oss.sgi.com
Cc: "David S. Miller" <davem@redhat.com>
Subject: [PATCH] small skbuff.[ch] tweaks
Date: Tue, 2 Sep 2003 01:16:25 -0700 [thread overview]
Message-ID: <20030902081625.GA52298@gaz.sfgoth.com> (raw)
This patch:
o Makes a couple inline functions in <linux/skbuff.h> take const arguments
as appropriate
o Obvious unlikely()/likely()/BUG_ON() conversions
Patch is versus 2.6.0-test4.
-Mitch
--- linux-2.6.0-test4-VIRGIN/include/linux/skbuff.h 2003-08-10 05:28:41.000000000 -0700
+++ linux-2.6.0-test4mnb1/include/linux/skbuff.h 2003-09-01 14:08:54.000000000 -0700
@@ -306,7 +306,7 @@
*
* Returns true if the queue is empty, false otherwise.
*/
-static inline int skb_queue_empty(struct sk_buff_head *list)
+static inline int skb_queue_empty(const struct sk_buff_head *list)
{
return list->next == (struct sk_buff *)list;
}
@@ -475,7 +475,7 @@
*
* Return the length of an &sk_buff queue.
*/
-static inline __u32 skb_queue_len(struct sk_buff_head *list_)
+static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
{
return list_->qlen;
}
@@ -1050,7 +1050,7 @@
int gfp_mask)
{
struct sk_buff *skb = alloc_skb(length + 16, gfp_mask);
- if (skb)
+ if (likely(skb))
skb_reserve(skb, 16);
return skb;
}
--- linux-2.6.0-test4-VIRGIN/net/core/skbuff.c 2003-08-22 13:47:28.000000000 -0700
+++ linux-2.6.0-test4mnb1/net/core/skbuff.c 2003-09-01 14:00:37.000000000 -0700
@@ -129,14 +129,17 @@
/* Get the HEAD */
skb = kmem_cache_alloc(skbuff_head_cache,
gfp_mask & ~__GFP_DMA);
- if (!skb)
+ if (unlikely(!skb))
goto out;
/* Get the DATA. Size must match skb_add_mtu(). */
size = SKB_DATA_ALIGN(size);
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
- if (!data)
- goto nodata;
+ if (unlikely(!data)) {
+ kmem_cache_free(skbuff_head_cache, skb);
+ skb = NULL;
+ goto out;
+ }
memset(skb, 0, offsetof(struct sk_buff, truesize));
skb->truesize = size + sizeof(struct sk_buff);
@@ -153,10 +156,6 @@
skb_shinfo(skb)->frag_list = NULL;
out:
return skb;
-nodata:
- kmem_cache_free(skbuff_head_cache, skb);
- skb = NULL;
- goto out;
}
@@ -218,7 +217,7 @@
void __kfree_skb(struct sk_buff *skb)
{
- if (skb->list) {
+ if (unlikely(skb->list)) {
printk(KERN_WARNING "Warning: kfree_skb passed an skb still "
"on a list (from %p).\n", NET_CALLER(skb));
BUG();
@@ -229,7 +228,7 @@
secpath_put(skb->sp);
#endif
if(skb->destructor) {
- if (in_irq())
+ if (unlikely(in_irq()))
printk(KERN_WARNING "Warning: kfree_skb on "
"hard IRQ %p\n", NET_CALLER(skb));
skb->destructor(skb);
@@ -261,7 +260,7 @@
{
struct sk_buff *n = kmem_cache_alloc(skbuff_head_cache, gfp_mask);
- if (!n)
+ if (unlikely(!n))
return NULL;
#define C(x) n->x = skb->x
@@ -395,7 +394,7 @@
*/
struct sk_buff *n = alloc_skb(skb->end - skb->head + skb->data_len,
gfp_mask);
- if (!n)
+ if (unlikely(!n))
return NULL;
/* Set the data pointer */
@@ -405,7 +404,7 @@
n->csum = skb->csum;
n->ip_summed = skb->ip_summed;
- if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len))
+ if (unlikely(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)))
BUG();
copy_skb_header(n, skb);
@@ -433,7 +432,7 @@
*/
struct sk_buff *n = alloc_skb(skb->end - skb->head, gfp_mask);
- if (!n)
+ if (unlikely(!n))
goto out;
/* Set the data pointer */
@@ -493,14 +492,13 @@
int size = nhead + (skb->end - skb->head) + ntail;
long off;
- if (skb_shared(skb))
- BUG();
+ BUG_ON(skb_shared(skb));
size = SKB_DATA_ALIGN(size);
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
- if (!data)
- goto nodata;
+ if (unlikely(!data))
+ return -ENOMEM;
/* Copy only real data... and, alas, header. This should be
* optimized for the cases when header is void. */
@@ -527,9 +525,6 @@
skb->cloned = 0;
atomic_set(&skb_shinfo(skb)->dataref, 1);
return 0;
-
-nodata:
- return -ENOMEM;
}
/* Make private copy of skb with writable head and some headroom */
@@ -543,8 +538,8 @@
skb2 = pskb_copy(skb, GFP_ATOMIC);
else {
skb2 = skb_clone(skb, GFP_ATOMIC);
- if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0,
- GFP_ATOMIC)) {
+ if (unlikely(skb2 && pskb_expand_head(skb2,
+ SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC))) {
kfree_skb(skb2);
skb2 = NULL;
}
@@ -582,7 +577,7 @@
*/
struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom,
gfp_mask);
- if (!n)
+ if (unlikely(!n))
return NULL;
skb_reserve(n, newheadroom);
@@ -591,7 +586,7 @@
skb_put(n, skb->len);
/* Copy the data only. */
- if (skb_copy_bits(skb, 0, n->data, skb->len))
+ if (unlikely(skb_copy_bits(skb, 0, n->data, skb->len)))
BUG();
copy_skb_header(n, skb);
@@ -625,7 +620,7 @@
nskb = skb_copy_expand(skb, skb_headroom(skb), skb_tailroom(skb) + pad, GFP_ATOMIC);
kfree_skb(skb);
- if (nskb)
+ if (likely(nskb))
memset(nskb->data+nskb->len, 0, pad);
return nskb;
}
@@ -645,9 +640,8 @@
int end = offset + skb_shinfo(skb)->frags[i].size;
if (end > len) {
if (skb_cloned(skb)) {
- if (!realloc)
- BUG();
- if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ BUG_ON(!realloc);
+ if (unlikely(pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
return -ENOMEM;
}
if (len <= offset) {
@@ -713,12 +707,12 @@
int i, k, eat = (skb->tail + delta) - skb->end;
if (eat > 0 || skb_cloned(skb)) {
- if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
- GFP_ATOMIC))
+ if (unlikely(pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
+ GFP_ATOMIC)))
return NULL;
}
- if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta))
+ if (unlikely(skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta)))
BUG();
/* Optimization: no fragments, no reasons to preestimate
@@ -748,8 +742,7 @@
struct sk_buff *insp = NULL;
do {
- if (!list)
- BUG();
+ BUG_ON(!list);
if (list->len <= eat) {
/* Eaten as whole. */
@@ -762,7 +755,7 @@
if (skb_shared(list)) {
/* Sucks! We need to fork list. :-( */
clone = skb_clone(list, GFP_ATOMIC);
- if (!clone)
+ if (unlikely(!clone))
return NULL;
insp = list->next;
list = clone;
@@ -771,7 +764,7 @@
* problems. */
insp = list;
}
- if (!pskb_pull(list, eat)) {
+ if (unlikely(!pskb_pull(list, eat))) {
if (clone)
kfree_skb(clone);
return NULL;
@@ -825,7 +818,7 @@
int i, copy;
int start = skb_headlen(skb);
- if (offset > (int)skb->len - len)
+ if (unlikely(offset > (int)skb->len - len))
goto fault;
/* Copy header. */
@@ -877,8 +870,8 @@
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- if (skb_copy_bits(list, offset - start,
- to, copy))
+ if (unlikely(skb_copy_bits(list, offset - start,
+ to, copy)))
goto fault;
if ((len -= copy) == 0)
return 0;
@@ -888,7 +881,7 @@
start = end;
}
}
- if (!len)
+ if (likely(!len))
return 0;
fault:
@@ -965,8 +958,7 @@
start = end;
}
}
- if (len)
- BUG();
+ BUG_ON(len);
return csum;
}
@@ -1048,8 +1040,7 @@
start = end;
}
}
- if (len)
- BUG();
+ BUG_ON(len);
return csum;
}
@@ -1063,8 +1054,7 @@
else
csstart = skb_headlen(skb);
- if (csstart > skb_headlen(skb))
- BUG();
+ BUG_ON(csstart > skb_headlen(skb));
memcpy(to, skb->data, csstart);
next reply other threads:[~2003-09-02 8:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-02 8:16 Mitchell Blank Jr [this message]
2003-09-02 8:58 ` [PATCH] small skbuff.[ch] tweaks Andi Kleen
2003-09-02 9:10 ` Mitchell Blank Jr
2003-09-02 9:04 ` Andi Kleen
2003-09-02 9:49 ` Mitchell Blank Jr
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