From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [V2 PATCH 2/9] macvtap: zerocopy: fix truesize underestimation Date: Wed, 02 May 2012 11:41:44 +0800 Message-ID: <20120502034144.11782.88947.stgit@amd-6168-8-1.englab.nay.redhat.com> References: <20120502033901.11782.13157.stgit@amd-6168-8-1.englab.nay.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: eric.dumazet@gmail.com, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ebiederm@xmission.com, davem@davemloft.net Return-path: In-Reply-To: <20120502033901.11782.13157.stgit@amd-6168-8-1.englab.nay.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org As the skb fragment were pinned/built from user pages, we should account the page instead of length for truesize. Signed-off-by: Jason Wang --- drivers/net/macvtap.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index bd4a70d..7cb2684 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -519,6 +519,7 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, struct page *page[MAX_SKB_FRAGS]; int num_pages; unsigned long base; + unsigned long truesize; len = from->iov_len - offset; if (!len) { @@ -533,10 +534,11 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, (num_pages > MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags)) /* put_page is in skb free */ return -EFAULT; + truesize = size * PAGE_SIZE; skb->data_len += len; skb->len += len; - skb->truesize += len; - atomic_add(len, &skb->sk->sk_wmem_alloc); + skb->truesize += truesize; + atomic_add(truesize, &skb->sk->sk_wmem_alloc); while (len) { int off = base & ~PAGE_MASK; int size = min_t(int, len, PAGE_SIZE - off);