diff options
| -rw-r--r-- | package/kernel/mac80211/patches/333-cfg80211-reuse-existing-page-fragments-in-A-MSDU-rx.patch | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/package/kernel/mac80211/patches/333-cfg80211-reuse-existing-page-fragments-in-A-MSDU-rx.patch b/package/kernel/mac80211/patches/333-cfg80211-reuse-existing-page-fragments-in-A-MSDU-rx.patch new file mode 100644 index 0000000000..6e2d0cf5b0 --- /dev/null +++ b/package/kernel/mac80211/patches/333-cfg80211-reuse-existing-page-fragments-in-A-MSDU-rx.patch @@ -0,0 +1,132 @@ +From: Felix Fietkau <nbd@openwrt.org> +Date: Mon, 8 Feb 2016 14:33:19 +0100 +Subject: [PATCH] cfg80211: reuse existing page fragments in A-MSDU rx + +This massively reduces data copying and thus improves rx performance + +Signed-off-by: Felix Fietkau <nbd@openwrt.org> +--- + +--- a/net/wireless/util.c ++++ b/net/wireless/util.c +@@ -644,23 +644,93 @@ int ieee80211_data_from_8023(struct sk_b + } + EXPORT_SYMBOL(ieee80211_data_from_8023); + ++static void ++__frame_add_frag(struct sk_buff *skb, struct page *page, ++ void *ptr, int len, int size) ++{ ++ struct skb_shared_info *sh = skb_shinfo(skb); ++ int page_offset; ++ ++ atomic_inc(&page->_count); ++ page_offset = ptr - page_address(page); ++ skb_add_rx_frag(skb, sh->nr_frags, page, page_offset, len, size); ++} ++ ++static void ++__ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame, ++ int offset, int len) ++{ ++ struct skb_shared_info *sh = skb_shinfo(skb); ++ const skb_frag_t *frag = &sh->frags[-1]; ++ struct page *frag_page; ++ void *frag_ptr; ++ int frag_len, frag_size; ++ int head_size = skb->len - skb->data_len; ++ int cur_len; ++ ++ frag_page = virt_to_head_page(skb->head); ++ frag_ptr = skb->data; ++ frag_size = head_size; ++ ++ while (offset >= frag_size) { ++ offset -= frag_size; ++ frag++; ++ frag_page = skb_frag_page(frag); ++ frag_ptr = skb_frag_address(frag); ++ frag_size = skb_frag_size(frag); ++ } ++ ++ frag_ptr += offset; ++ frag_len = frag_size - offset; ++ ++ cur_len = min(len, frag_len); ++ ++ __frame_add_frag(frame, frag_page, frag_ptr, cur_len, frag_size); ++ len -= cur_len; ++ ++ while (len > 0) { ++ frag++; ++ frag_len = skb_frag_size(frag); ++ cur_len = min(len, frag_len); ++ __frame_add_frag(frame, skb_frag_page(frag), ++ skb_frag_address(frag), cur_len, frag_len); ++ len -= cur_len; ++ } ++} ++ + static struct sk_buff * + __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen, +- int offset, int len) ++ int offset, int len, bool reuse_frag) + { + struct sk_buff *frame; ++ int cur_len = len; + + if (skb->len - offset < len) + return NULL; + + /* ++ * When reusing framents, copy some data to the head to simplify ++ * ethernet header handling and speed up protocol header processing ++ * in the stack later. ++ */ ++ if (reuse_frag) ++ cur_len = min_t(int, len, 32); ++ ++ /* + * Allocate and reserve two bytes more for payload + * alignment since sizeof(struct ethhdr) is 14. + */ +- frame = dev_alloc_skb(hlen + sizeof(struct ethhdr) + 2 + len); ++ frame = dev_alloc_skb(hlen + sizeof(struct ethhdr) + 2 + cur_len); + + skb_reserve(frame, hlen + sizeof(struct ethhdr) + 2); +- skb_copy_bits(skb, offset, skb_put(frame, len), len); ++ skb_copy_bits(skb, offset, skb_put(frame, cur_len), cur_len); ++ ++ len -= cur_len; ++ if (!len) ++ return frame; ++ ++ offset += cur_len; ++ __ieee80211_amsdu_copy_frag(skb, frame, offset, len); + + return frame; + } +@@ -676,6 +746,7 @@ void ieee80211_amsdu_to_8023s(struct sk_ + u8 *payload; + int offset = 0, remaining, err; + struct ethhdr eth; ++ bool reuse_frag = skb->head_frag && !skb_has_frag_list(skb); + bool reuse_skb = false; + bool last = false; + +@@ -703,12 +774,13 @@ void ieee80211_amsdu_to_8023s(struct sk_ + offset += sizeof(struct ethhdr); + /* reuse skb for the last subframe */ + last = remaining <= subframe_len + padding; +- if (!skb_is_nonlinear(skb) && last) { ++ if (!skb_is_nonlinear(skb) && !reuse_frag && last) { + skb_pull(skb, offset); + frame = skb; + reuse_skb = true; + } else { +- frame = __ieee80211_amsdu_copy(skb, hlen, offset, len); ++ frame = __ieee80211_amsdu_copy(skb, hlen, offset, len, ++ reuse_frag); + if (!frame) + goto purge; + |