From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: (2) (2) [Kernel][NET] Bug report on packet defragmenting Date: Wed, 7 Nov 2018 20:26:02 -0800 Message-ID: <8b2209af-1221-f4f5-54e5-d9f5a503373e@gmail.com> References: <1771721f-40fd-0042-b603-5ed763c54378@gmail.com> <91b43bec-cb19-b94b-8ee3-26979e3a19d1@gmail.com> <20181108012927epcms1p47f719c1908da64a378690362901644ee@epcms1p4> <20181108020523epcms1p55a0c28d3e881a079231fe813258602f6@epcms1p5> <20181108041001epcms1p6c83831e3ef0d66b9591c2aca25d5841b@epcms1p6> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit To: soukjin.bae@samsung.com, "netdev@vger.kernel.org" Return-path: Received: from mail-pg1-f177.google.com ([209.85.215.177]:39535 "EHLO mail-pg1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728499AbeKHN7i (ORCPT ); Thu, 8 Nov 2018 08:59:38 -0500 Received: by mail-pg1-f177.google.com with SMTP id r9-v6so8295910pgv.6 for ; Wed, 07 Nov 2018 20:26:05 -0800 (PST) In-Reply-To: <20181108041001epcms1p6c83831e3ef0d66b9591c2aca25d5841b@epcms1p6> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 11/07/2018 08:10 PM, 배석진 wrote: >> --------- Original Message --------- >> Sender : Eric Dumazet  >> Date : 2018-11-08 12:57 (GMT+9) >> Title : Re: (2) [Kernel][NET] Bug report on packet defragmenting >>   >> On 11/07/2018 07:24 PM, Eric Dumazet wrote: >> >>>  Sure, it is better if RPS is smarter, but if there is a bug in IPv6 defrag unit >>>  we must investigate and root-cause it. >>   >> BTW, IPv4 defrag seems to have the same issue. >   > > yes, it could be. > key point isn't limitted to ipv6. > > maybe because of faster air-network and modem, > it looks like occure more often and we got recognized that. > > anyway, > we'll apply our patch to resolve this problem. Yeah, and I will fix the defrag units. We can not rely on other layers doing proper no-reorder logic for us. Problem here is that multiple cpus attempt concurrent rhashtable_insert_fast() and do not properly recover in case -EEXIST is returned. This is silly, of course :/