From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] xen/netback: Calculate the number of SKB slots required correctly Date: Thu, 24 May 2012 16:21:17 -0400 (EDT) Message-ID: <20120524.162117.2167559109226305167.davem@davemloft.net> References: <1337876767-16041-1-git-send-email-simon.graham@citrix.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1337876767-16041-1-git-send-email-simon.graham@citrix.com> Sender: netdev-owner@vger.kernel.org To: simon.graham@citrix.com Cc: Ian.Campbell@citrix.com, konrad.wilk@oracle.com, xen-devel@lists.xensource.com, netdev@vger.kernel.org, bhutchings@solarflare.com, adnan.misherfi@oracle.com List-Id: xen-devel@lists.xenproject.org From: Simon Graham Date: Thu, 24 May 2012 12:26:07 -0400 > When calculating the number of slots required for a packet header, the code > was reserving too many slots if the header crossed a page boundary. Since > netbk_gop_skb copies the header to the start of the page, the count of > slots required for the header should be based solely on the header size. > > This problem is easy to reproduce if a VIF is bridged to a USB 3G modem > device as the skb->data value always starts near the end of the first page. > > Signed-off-by: Simon Graham Applied.