diff options
Diffstat (limited to 'net/core/skbuff.c')
-rw-r--r-- | net/core/skbuff.c | 86 |
1 files changed, 40 insertions, 46 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index e33ebae519c8..cdc28598f4ef 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -340,43 +340,57 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) EXPORT_SYMBOL(build_skb); struct netdev_alloc_cache { - struct page *page; - unsigned int offset; - unsigned int pagecnt_bias; + struct page_frag frag; + /* we maintain a pagecount bias, so that we dont dirty cache line + * containing page->_count every time we allocate a fragment. + */ + unsigned int pagecnt_bias; }; static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache); -#define NETDEV_PAGECNT_BIAS (PAGE_SIZE / SMP_CACHE_BYTES) +#define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768) +#define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER) +#define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) { struct netdev_alloc_cache *nc; void *data = NULL; + int order; unsigned long flags; local_irq_save(flags); nc = &__get_cpu_var(netdev_alloc_cache); - if (unlikely(!nc->page)) { + if (unlikely(!nc->frag.page)) { refill: - nc->page = alloc_page(gfp_mask); - if (unlikely(!nc->page)) - goto end; + for (order = NETDEV_FRAG_PAGE_MAX_ORDER; ;) { + gfp_t gfp = gfp_mask; + + if (order) + gfp |= __GFP_COMP | __GFP_NOWARN; + nc->frag.page = alloc_pages(gfp, order); + if (likely(nc->frag.page)) + break; + if (--order < 0) + goto end; + } + nc->frag.size = PAGE_SIZE << order; recycle: - atomic_set(&nc->page->_count, NETDEV_PAGECNT_BIAS); - nc->pagecnt_bias = NETDEV_PAGECNT_BIAS; - nc->offset = 0; + atomic_set(&nc->frag.page->_count, NETDEV_PAGECNT_MAX_BIAS); + nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS; + nc->frag.offset = 0; } - if (nc->offset + fragsz > PAGE_SIZE) { + if (nc->frag.offset + fragsz > nc->frag.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)) + if ((atomic_read(&nc->frag.page->_count) == nc->pagecnt_bias) || + atomic_sub_and_test(nc->pagecnt_bias, &nc->frag.page->_count)) goto recycle; goto refill; } - data = page_address(nc->page) + nc->offset; - nc->offset += fragsz; + data = page_address(nc->frag.page) + nc->frag.offset; + nc->frag.offset += fragsz; nc->pagecnt_bias--; end: local_irq_restore(flags); @@ -1655,38 +1669,19 @@ static struct page *linear_to_page(struct page *page, unsigned int *len, unsigned int *offset, struct sk_buff *skb, struct sock *sk) { - struct page *p = sk->sk_sndmsg_page; - unsigned int off; - - if (!p) { -new_page: - p = sk->sk_sndmsg_page = alloc_pages(sk->sk_allocation, 0); - if (!p) - return NULL; + struct page_frag *pfrag = sk_page_frag(sk); - off = sk->sk_sndmsg_off = 0; - /* hold one ref to this page until it's full */ - } else { - unsigned int mlen; - - /* If we are the only user of the page, we can reset offset */ - if (page_count(p) == 1) - sk->sk_sndmsg_off = 0; - off = sk->sk_sndmsg_off; - mlen = PAGE_SIZE - off; - if (mlen < 64 && mlen < *len) { - put_page(p); - goto new_page; - } + if (!sk_page_frag_refill(sk, pfrag)) + return NULL; - *len = min_t(unsigned int, *len, mlen); - } + *len = min_t(unsigned int, *len, pfrag->size - pfrag->offset); - memcpy(page_address(p) + off, page_address(page) + *offset, *len); - sk->sk_sndmsg_off += *len; - *offset = off; + memcpy(page_address(pfrag->page) + pfrag->offset, + page_address(page) + *offset, *len); + *offset = pfrag->offset; + pfrag->offset += *len; - return p; + return pfrag->page; } static bool spd_can_coalesce(const struct splice_pipe_desc *spd, @@ -3488,8 +3483,7 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS) return false; - delta = from->truesize - - SKB_TRUESIZE(skb_end_pointer(from) - from->head); + delta = from->truesize - SKB_TRUESIZE(skb_end_offset(from)); } WARN_ON_ONCE(delta < len); |