diff options
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 71 |
1 files changed, 39 insertions, 32 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d124306b81fd..368f65c15e4f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -160,8 +160,8 @@ static void skb_under_panic(struct sk_buff *skb, int sz, void *here) * @node: numa node to allocate memory on * * Allocate a new &sk_buff. The returned buffer has no headroom and a - * tail room of size bytes. The object has a reference count of one. - * The return is the buffer. On a failure the return is %NULL. + * tail room of at least size bytes. The object has a reference count + * of one. The return is the buffer. On a failure the return is %NULL. * * Buffers may only be allocated from interrupts using a @gfp_mask of * %GFP_ATOMIC. @@ -296,9 +296,12 @@ EXPORT_SYMBOL(build_skb); struct netdev_alloc_cache { struct page *page; unsigned int offset; + unsigned int pagecnt_bias; }; static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache); +#define NETDEV_PAGECNT_BIAS (PAGE_SIZE / SMP_CACHE_BYTES) + /** * netdev_alloc_frag - allocate a page fragment * @fragsz: fragment size @@ -317,17 +320,26 @@ void *netdev_alloc_frag(unsigned int fragsz) if (unlikely(!nc->page)) { refill: nc->page = alloc_page(GFP_ATOMIC | __GFP_COLD); + if (unlikely(!nc->page)) + goto end; +recycle: + atomic_set(&nc->page->_count, NETDEV_PAGECNT_BIAS); + nc->pagecnt_bias = NETDEV_PAGECNT_BIAS; nc->offset = 0; } - if (likely(nc->page)) { - if (nc->offset + fragsz > PAGE_SIZE) { - put_page(nc->page); - goto refill; - } - data = page_address(nc->page) + nc->offset; - nc->offset += fragsz; - get_page(nc->page); + + if (nc->offset + fragsz > PAGE_SIZE) { + /* avoid unnecessary locked operations if possible */ + if ((atomic_read(&nc->page->_count) == nc->pagecnt_bias) || + atomic_sub_and_test(nc->pagecnt_bias, &nc->page->_count)) + goto recycle; + goto refill; } + + data = page_address(nc->page) + nc->offset; + nc->offset += fragsz; + nc->pagecnt_bias--; +end: local_irq_restore(flags); return data; } @@ -713,7 +725,8 @@ struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src) } EXPORT_SYMBOL_GPL(skb_morph); -/* skb_copy_ubufs - copy userspace skb frags buffers to kernel +/** + * skb_copy_ubufs - copy userspace skb frags buffers to kernel * @skb: the skb to modify * @gfp_mask: allocation priority * @@ -738,7 +751,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) u8 *vaddr; skb_frag_t *f = &skb_shinfo(skb)->frags[i]; - page = alloc_page(GFP_ATOMIC); + page = alloc_page(gfp_mask); if (!page) { while (head) { struct page *next = (struct page *)head->private; @@ -756,22 +769,22 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) } /* skb frags release userspace buffers */ - for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) + for (i = 0; i < num_frags; i++) skb_frag_unref(skb, i); uarg->callback(uarg); /* skb frags point to kernel buffers */ - for (i = skb_shinfo(skb)->nr_frags; i > 0; i--) { - __skb_fill_page_desc(skb, i-1, head, 0, - skb_shinfo(skb)->frags[i - 1].size); + for (i = num_frags - 1; i >= 0; i--) { + __skb_fill_page_desc(skb, i, head, 0, + skb_shinfo(skb)->frags[i].size); head = (struct page *)head->private; } skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY; return 0; } - +EXPORT_SYMBOL_GPL(skb_copy_ubufs); /** * skb_clone - duplicate an sk_buff @@ -791,10 +804,8 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) { struct sk_buff *n; - if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) { - if (skb_copy_ubufs(skb, gfp_mask)) - return NULL; - } + if (skb_orphan_frags(skb, gfp_mask)) + return NULL; n = skb + 1; if (skb->fclone == SKB_FCLONE_ORIG && @@ -914,12 +925,10 @@ struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, gfp_t gfp_mask) if (skb_shinfo(skb)->nr_frags) { int i; - if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) { - if (skb_copy_ubufs(skb, gfp_mask)) { - kfree_skb(n); - n = NULL; - goto out; - } + if (skb_orphan_frags(skb, gfp_mask)) { + kfree_skb(n); + n = NULL; + goto out; } for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i]; @@ -992,10 +1001,8 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, */ if (skb_cloned(skb)) { /* copy this zero copy skb frags */ - if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) { - if (skb_copy_ubufs(skb, gfp_mask)) - goto nofrags; - } + if (skb_orphan_frags(skb, gfp_mask)) + goto nofrags; for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) skb_frag_ref(skb, i); @@ -2614,7 +2621,7 @@ unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, EXPORT_SYMBOL(skb_find_text); /** - * skb_append_datato_frags: - append the user data to a skb + * skb_append_datato_frags - append the user data to a skb * @sk: sock structure * @skb: skb structure to be appened with user data. * @getfrag: call back function to be used for getting the user data |