On Mon, Jun 10, 2019 at 01:13:16AM +0000, nobuhiro1.iwamatsu@xxxxxxxxxxxxx wrote: > Hi again. > > > -----Original Message----- > > From: stable-owner@xxxxxxxxxxxxxxx > > [mailto:stable-owner@xxxxxxxxxxxxxxx] On Behalf Of Nobuhiro Iwamatsu > > Sent: Monday, June 10, 2019 10:10 AM > > To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > Cc: linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; Alan Maguire > > <alan.maguire@xxxxxxxxxx>; David Ahern <dsahern@xxxxxxxxx>; David S. > > Miller <davem@xxxxxxxxxxxxx> > > Subject: Re: [PATCH 4.14 03/35] neighbor: Call __ipv4_neigh_lookup_noref > > in neigh_xmit > > > > Hi, > > > > On Sun, Jun 09, 2019 at 06:42:09PM +0200, Greg Kroah-Hartman wrote: > > > From: David Ahern <dsahern@xxxxxxxxx> > > > > > > [ Upstream commit 4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 ] > > > > > > Commit cd9ff4de0107 changed the key for IFF_POINTOPOINT devices to > > > INADDR_ANY but neigh_xmit which is used for MPLS encapsulations was > > > not updated to use the altered key. The result is that every packet > > Tx > > > does a lookup on the gateway address which does not find an entry, a > > > new one is created only to find the existing one in the table right > > > before the insert since arp_constructor was updated to reset the > > > primary key. This is seen in the allocs and destroys counters: > > > ip -s -4 ntable show | head -10 | grep alloc > > > > > > which increase for each packet showing the unnecessary overhread. > > > > > > Fix by having neigh_xmit use __ipv4_neigh_lookup_noref for > > NEIGH_ARP_TABLE. > > > > > > Fixes: cd9ff4de0107 ("ipv4: Make neigh lookup keys for > > > loopback/point-to-point devices be INADDR_ANY") > > > Reported-by: Alan Maguire <alan.maguire@xxxxxxxxxx> > > > Signed-off-by: David Ahern <dsahern@xxxxxxxxx> > > > Tested-by: Alan Maguire <alan.maguire@xxxxxxxxxx> > > > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> > > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > > --- > > > > This commit also requires the following commit: > > > > commit 9b3040a6aafd7898ece7fc7efcbca71e42aa8069 > > Author: David Ahern <dsahern@xxxxxxxxx> > > Date: Sun May 5 11:16:20 2019 -0700 > > > > ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled > > > > Define __ipv4_neigh_lookup_noref to return NULL when CONFIG_INET is > > disabled. > > > > Fixes: 4b2a2bfeb3f0 ("neighbor: Call __ipv4_neigh_lookup_noref in > > neigh_xmit") > > Reported-by: kbuild test robot <lkp@xxxxxxxxx> > > Signed-off-by: David Ahern <dsahern@xxxxxxxxx> > > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> > > > > And this is also necessary for 4.4.y, 4.14.y, 4.19.y and 5.1.y. > > 4.4.y, 4.9.y, 4.19.y and 5.1.y. Thanks for the information, now queued up everywhere. greg k-h
