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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99404C64EBC for ; Thu, 4 Oct 2018 17:01:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5323720652 for ; Thu, 4 Oct 2018 17:01:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5323720652 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbeJDXzq (ORCPT ); Thu, 4 Oct 2018 19:55:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49954 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727616AbeJDXzo (ORCPT ); Thu, 4 Oct 2018 19:55:44 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DA17D30E5F8D; Thu, 4 Oct 2018 16:54:35 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-149.rdu2.redhat.com [10.10.120.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id C6F7D60191; Thu, 4 Oct 2018 16:54:34 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <153864184110.20296.16498481420320274305.stgit@warthog.procyon.org.uk> To: David Ahern Cc: dhowells@redhat.com, netdev@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next] udp: Add tracepoints to monitor skbs going in and out of a UDP socket MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <25667.1538672073.1@warthog.procyon.org.uk> Date: Thu, 04 Oct 2018 17:54:33 +0100 Message-ID: <25668.1538672073@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Thu, 04 Oct 2018 16:54:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David Ahern wrote: > These do not add any real value. You are only dumping the skb address, Not in and of themselves, no - but in combination with tracepoints elsewhere, where you can use the skb address as a key to follow the lifetime of a particular skb. > and you can get the same effect with a probe on the function and dumping > the value of the register with the skb argument. Installing a probe requires various preconditions, including your kernel not being locked down and having the source around AIUI. Anyway, I've no especially strong feelings about this patch - it's been useful for me and it might be useful to others. David