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-rw-r--r--net/core/skbuff.c46
1 files changed, 30 insertions, 16 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 2ede3cf..607a70f 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);