From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: UDP sockets oddities Date: Fri, 25 Aug 2017 18:17:34 -0700 Message-ID: References: <3fed7679-0e19-8a0a-eee6-11baa5654fac@gmail.com> <1503527210.2499.63.camel@edumazet-glaptop3.roam.corp.google.com> <9a9c1c94-4902-2ec9-d216-3f5cfb3044af@gmail.com> <1503529476.2499.65.camel@edumazet-glaptop3.roam.corp.google.com> <6c88e440-3f36-858d-1a08-bd32a2c66f4e@gmail.com> <1503535426.2499.66.camel@edumazet-glaptop3.roam.corp.google.com> <4adb4b66-590c-c55a-44aa-27dd409ce14f@gmail.com> <3c44d27e-27d9-e9c4-04b3-17c0366e60d9@gmail.com> <1503705440.11498.9.camel@edumazet-glaptop3.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: netdev@vger.kernel.org, edumazet@gmail.com, pabeni@redhat.com, willemb@google.com, davem@davemloft.net To: Eric Dumazet Return-path: Received: from mail-qk0-f179.google.com ([209.85.220.179]:34924 "EHLO mail-qk0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426AbdHZBRj (ORCPT ); Fri, 25 Aug 2017 21:17:39 -0400 Received: by mail-qk0-f179.google.com with SMTP id p67so6627658qkd.2 for ; Fri, 25 Aug 2017 18:17:38 -0700 (PDT) In-Reply-To: <1503705440.11498.9.camel@edumazet-glaptop3.roam.corp.google.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 08/25/2017 04:57 PM, Eric Dumazet wrote: > On Fri, 2017-08-25 at 16:18 -0700, Florian Fainelli wrote: > >> Eric, are there areas of the stack where we are allowed to drop packets, >> not propagate that back to write(2) and also not increment any counter >> either, or maybe I am not looking where I should... > > What happens if you increase these sysctls ? I don't see packet loss after I tweak these two sysctls according to your suggestions. Tweaking eth0's sysctls did not change anything, but tweaking gphy's sysctl resolved the loss. This was a little surprising considering that gphy is an IFF_NO_QUEUE interface and eth0 is the conduit interface that does the real transmission. Does that make sense with respect to what I reported earlier? Should I try to dump the neigh stats? Thanks! > > grep . `find /proc/sys|grep unres_qlen` > > > unres_qlen_bytes -> 2000000 > unres_qlen -> 10000 > > -- Florian