From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: kernel 3.2.27 on arm: WARNING: at mm/page_alloc.c:2109 __alloc_pages_nodemask+0x1d4/0x68c() Date: Fri, 05 Oct 2012 17:04:00 +0200 Message-ID: <1349449440.21172.118.camel@edumazet-glaptop> References: <20120829002548.GA7063@aldebaran.gro-tsen.net> <1349366521.2532.12.camel@sakura.staff.proxad.net> <1349368171.16011.79.camel@edumazet-glaptop> <1349422868.21172.38.camel@edumazet-glaptop> <1349434194.16710.44.camel@sakura.staff.proxad.net> <1349439732.21172.52.camel@edumazet-glaptop> <1349441509.28867.17.camel@sakura.staff.proxad.net> <1349442173.21172.66.camel@edumazet-glaptop> <1349448659.28867.27.camel@sakura.staff.proxad.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: David Madore , Francois Romieu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Hugh Dickins To: mbizon@freebox.fr Return-path: In-Reply-To: <1349448659.28867.27.camel@sakura.staff.proxad.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 2012-10-05 at 16:50 +0200, Maxime Bizon wrote: > On Fri, 2012-10-05 at 15:02 +0200, Eric Dumazet wrote: > > > On Fri, 2012-10-05 at 14:51 +0200, Maxime Bizon wrote: > > > > > > New convention would be : pass number of needed bytes after current > > > > tail, not after current end. > > > > > > Fully agree on this > > > > > > > Here is the proposal : > > Looks fine > > What is your plan for the actual pskb_expand_head() code now that you > will have absolute values for headroom & tailroom ? > They stay relative values. For example, netlink_trim() really wants to shrink the skb head. > Because there will still be callers that have no clue of required > tailroom (nor further headroom requirement), like skb_cow() in > vlan_reorder_header(). > What I plan is to not shrink size, unless specifically asked. Its 3.8 material anyway, so a stable fix is needed on skb_recycle() and NET_SKB_PAD minimal value.