From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A14BC433EF for ; Wed, 16 Mar 2022 21:05:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356490AbiCPVGr (ORCPT ); Wed, 16 Mar 2022 17:06:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237976AbiCPVGo (ORCPT ); Wed, 16 Mar 2022 17:06:44 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 300A8E07; Wed, 16 Mar 2022 14:05:29 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A1DE5B81B9C; Wed, 16 Mar 2022 21:05:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BD4BC340E9; Wed, 16 Mar 2022 21:05:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647464726; bh=W+zVvbLr7763wZE7CgF92ost1JLexy2r+814x1pEmOs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qPzMsqMhDbr3dM3KZn8BzClGJi9v4nw9L8DR8Y1naJaiJvPPJSQFYgWaWspeKVMOC lHJjk8FRhXUO95yVvlezRqNVkitKDXUnX23LREc20ccSSFgbBdzjXDFSuL5EZMMwQR ibISh0E6UntORZRAv8m/aJ0gVrWwuNPl02MQIMPuIhhKmmpwqXJvEVf2vS5Q30Cyq7 vN6FvtKNfRbITESqVm7OtbH2AS1vln8WdbbN41pHUsG8/teOLu5nj8VsRiH3F4syyQ T3h+Y3wtggjhAWfN4SK9JtxWCqEmGsJSP9JTXaCWOKqR6fWmEzBvYsGLOGkDx+/sBI 2G3fiTJUgjiyA== Message-ID: <8f6d5115-1158-7276-b991-31253476326b@kernel.org> Date: Wed, 16 Mar 2022 15:05:23 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH net-next 1/3] net: gre_demux: add skb drop reasons to gre_rcv() Content-Language: en-US To: Jakub Kicinski Cc: menglong8.dong@gmail.com, rostedt@goodmis.org, mingo@redhat.com, xeb@mail.ru, davem@davemloft.net, yoshfuji@linux-ipv6.org, imagedong@tencent.com, edumazet@google.com, kafai@fb.com, talalahmad@google.com, keescook@chromium.org, alobakin@pm.me, flyingpeng@tencent.com, mengensun@tencent.com, dongli.zhang@oracle.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Biao Jiang References: <20220314133312.336653-1-imagedong@tencent.com> <20220314133312.336653-2-imagedong@tencent.com> <20220315200847.68c2efee@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20220315215553.676a5d24@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <30b0991a-8c41-2571-b1b6-9edc7dc9c702@kernel.org> <20220316115734.1899bb11@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> From: David Ahern In-Reply-To: <20220316115734.1899bb11@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/16/22 12:57 PM, Jakub Kicinski wrote: > On Wed, 16 Mar 2022 08:56:14 -0600 David Ahern wrote: >>> That's certainly true. I wonder if there is a systematic way of >>> approaching these additions that'd help us picking the points were >>> we add reasons less of a judgment call. >> >> In my head it's split between OS housekeeping and user visible data. >> Housekeeping side of it is more the technical failure points like skb >> manipulations - maybe interesting to a user collecting stats about how a >> node is performing, but more than likely not. IMHO, those are ignored >> for now (NOT_SPECIFIED). >> >> The immediate big win is for packets from a network where an analysis >> can show code location (instruction pointer), user focused reason (csum >> failure, 'otherhost', no socket open, no socket buffer space, ...) and >> traceable to a specific host (headers in skb data). > > Maybe I'm oversimplifying but would that mean first order of business > is to have drop codes for where we already bump MIB exception stats? That was the original motivation and it has since spun out of control - walking the code base and assigning unique drop reasons for every single call to kfree_skb.