From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751678Ab2DPGQo (ORCPT ); Mon, 16 Apr 2012 02:16:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49560 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751577Ab2DPGQl (ORCPT ); Mon, 16 Apr 2012 02:16:41 -0400 Subject: [PATCH 2/6] macvtap: zerocopy: fix truesize underestimation To: netdev@vger.kernel.org, xma@us.ibm.com, davem@davemloft.net, linux-kernel@vger.kernel.org, mst@redhat.com From: Jason Wang Cc: ebiederm@xmission.com Date: Mon, 16 Apr 2012 14:07:59 +0800 Message-ID: <20120416060758.14140.40252.stgit@intel-e5620-16-2.englab.nay.redhat.com> In-Reply-To: <20120416060749.14140.19433.stgit@intel-e5620-16-2.englab.nay.redhat.com> References: <20120416060749.14140.19433.stgit@intel-e5620-16-2.englab.nay.redhat.com> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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);