From 715dc1f342713816d1be1c37643a2c9e6ee181a7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 2 May 2012 23:33:21 +0000 Subject: net: Fix truesize accounting in skb_gro_receive() GRO is very optimistic in skb truesize estimates, only taking into account the used part of fragments. Be conservative, and use more precise computation, so that bloated GRO skbs can be collapsed eventually. Signed-off-by: Eric Dumazet Cc: Alexander Duyck Cc: Jeff Kirsher Acked-by: Alexander Duyck Signed-off-by: David S. Miller --- net/core/skbuff.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9e8caa0c4f7..e1f8bbaadf5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2871,6 +2871,7 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) unsigned int len = skb_gro_len(skb); unsigned int offset = skb_gro_offset(skb); unsigned int headlen = skb_headlen(skb); + unsigned int delta_truesize; if (p->len + len >= 65536) return -E2BIG; @@ -2900,11 +2901,14 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) frag->page_offset += offset; skb_frag_size_sub(frag, offset); + /* all fragments truesize : remove (head size + sk_buff) */ + delta_truesize = skb->truesize - SKB_TRUESIZE(skb_end_pointer(skb) - skb->head); + skb->truesize -= skb->data_len; skb->len -= skb->data_len; skb->data_len = 0; - NAPI_GRO_CB(skb)->free = 1; + NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE; goto done; } else if (skb->head_frag) { int nr_frags = pinfo->nr_frags; @@ -2929,6 +2933,7 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags); /* We dont need to clear skbinfo->nr_frags here */ + delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD; goto done; } else if (skb_gro_len(p) != pinfo->gso_size) @@ -2971,7 +2976,7 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) p = nskb; merge: - p->truesize += skb->truesize - len; + delta_truesize = skb->truesize; if (offset > headlen) { unsigned int eat = offset - headlen; @@ -2991,7 +2996,7 @@ merge: done: NAPI_GRO_CB(p)->count++; p->data_len += len; - p->truesize += len; + p->truesize += delta_truesize; p->len += len; NAPI_GRO_CB(skb)->same_flow = 1; -- cgit v1.2.3