From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Fernandes Date: Sat, 25 May 2019 18:18:18 +0000 Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs Message-Id: <20190525181818.GA225569@google.com> List-Id: References: <20190524234933.5133-1-joel@joelfernandes.org> <20190524232458.4bcf4eb4@gandalf.local.home> <20190525081444.GC197789@google.com> <20190525070826.16f76ee7@gandalf.local.home> <20190525141954.GA176647@google.com> <20190525155035.GE28207@linux.ibm.com> <20190525181407.GA220326@google.com> In-Reply-To: <20190525181407.GA220326@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Paul E. McKenney" Cc: Steven Rostedt , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Ingo Molnar , Jonathan Corbet , Josh Triplett , kvm-ppc@vger.kernel.org, Lai Jiangshan , linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Mathieu Desnoyers , Michael Ellerman , Miguel Ojeda , Paul Mackerras , rcu@vger.kernel.org On Sat, May 25, 2019 at 02:14:07PM -0400, Joel Fernandes wrote: [snip] > > That aside, if we are going to change the name of an API that is > > used 160 places throughout the tree, we would need to have a pretty > > good justification. Without such a justification, it will just look > > like pointless churn to the various developers and maintainers on the > > receiving end of the patches. > > Actually, the API name change is not something I want to do, it is Steven > suggestion. My suggestion is let us just delete _raw_notrace and just use the > _raw API for tracing, since _raw doesn't do any tracing anyway. Steve pointed > that _raw_notrace does sparse checking unlike _raw, but I think that isn't an > issue since _raw doesn't do such checking at the moment anyway.. (if possible > check my cover letter again for details/motivation of this series). Come to think of it, if we/I succeed in adding lockdep checking in _raw, then we can just keep the current APIs and not delete anything. And we can have _raw_notrace skip the lockdep checks. The sparse check question would still be an open one though, since _raw doesn't do sparse checks at the moment unlike _raw_notrace as Steve pointed. Thanks, - Joel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 75B4A7D2F0 for ; Sat, 25 May 2019 18:18:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727085AbfEYSSW (ORCPT ); Sat, 25 May 2019 14:18:22 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:35956 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727334AbfEYSSV (ORCPT ); Sat, 25 May 2019 14:18:21 -0400 Received: by mail-pg1-f196.google.com with SMTP id a3so6817139pgb.3 for ; Sat, 25 May 2019 11:18:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=pwUwT3IH5HpGo/L8sP6//cCZtClp5/ip6vUnZdkkz+4=; b=kkcebdlaAxI4tg4ycJmEqrzHnyewgh+jjzD8JuWykQMD1lxIZbs14DxRaS3JzJWrkx D3zUk40qEzDf9b4/+3m3e4ZQvAeZltgNBFxxlJjzMPDywJcvPdcoFqhPgZYDwqU6gPKo ZKBP/5ISTo1G00dTfWL1Nmxp2HkYKifVw8IVU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=pwUwT3IH5HpGo/L8sP6//cCZtClp5/ip6vUnZdkkz+4=; b=qYj0Pf/LUkv6BPchU3U4w1DU0WeWqQVOxKC1KVEBUATPdvyIoivKQaa+E2MadQJZvw 7lj2IAZe20WO34UinU8QQsUx6Qegkh4BNSVseVD3WfxFqG4d0n66gCpplxcsojFHCF7D 4oDg4ZZRa7abhjr/W2ek2i+kWkoo/ktralXXVepxp34FCRGtB1GSUmWCjiqPAJ2IbCAL l2I682gP+XILjb/RKC4TJWkDsazrmeaHh7OrDpdLT5F5AnrLSjum8+e+Ldl2MH6RGHdm 9oMA7xeP2KSgejIWPaI4NqnmmisXMmu9gW6dsnPnd0ht06S+xaEkHm1LLQqrZY220rxH PmFQ== X-Gm-Message-State: APjAAAUYLGIRvk3A74JJgeslB6rd4USYGjTsCl0qxHP/Vxg04fbVJhmA /6ZK9Sc0ZVK2ByIkcyXGyCA6Sw== X-Google-Smtp-Source: APXvYqx/tYCXEdllU2F4/1JetbgrhH8TFsHxXRye9Amlmvbkp4RD4ve2+88VYqD+upEJsBYYCIqDXw== X-Received: by 2002:aa7:8554:: with SMTP id y20mr121952964pfn.258.1558808300867; Sat, 25 May 2019 11:18:20 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id s24sm6537148pfe.57.2019.05.25.11.18.19 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 25 May 2019 11:18:20 -0700 (PDT) Date: Sat, 25 May 2019 14:18:18 -0400 From: Joel Fernandes To: "Paul E. McKenney" Cc: Steven Rostedt , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Ingo Molnar , Jonathan Corbet , Josh Triplett , kvm-ppc@vger.kernel.org, Lai Jiangshan , linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Mathieu Desnoyers , Michael Ellerman , Miguel Ojeda , Paul Mackerras , rcu@vger.kernel.org Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs Message-ID: <20190525181818.GA225569@google.com> References: <20190524234933.5133-1-joel@joelfernandes.org> <20190524232458.4bcf4eb4@gandalf.local.home> <20190525081444.GC197789@google.com> <20190525070826.16f76ee7@gandalf.local.home> <20190525141954.GA176647@google.com> <20190525155035.GE28207@linux.ibm.com> <20190525181407.GA220326@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190525181407.GA220326@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Sat, May 25, 2019 at 02:14:07PM -0400, Joel Fernandes wrote: [snip] > > That aside, if we are going to change the name of an API that is > > used 160 places throughout the tree, we would need to have a pretty > > good justification. Without such a justification, it will just look > > like pointless churn to the various developers and maintainers on the > > receiving end of the patches. > > Actually, the API name change is not something I want to do, it is Steven > suggestion. My suggestion is let us just delete _raw_notrace and just use the > _raw API for tracing, since _raw doesn't do any tracing anyway. Steve pointed > that _raw_notrace does sparse checking unlike _raw, but I think that isn't an > issue since _raw doesn't do such checking at the moment anyway.. (if possible > check my cover letter again for details/motivation of this series). Come to think of it, if we/I succeed in adding lockdep checking in _raw, then we can just keep the current APIs and not delete anything. And we can have _raw_notrace skip the lockdep checks. The sparse check question would still be an open one though, since _raw doesn't do sparse checks at the moment unlike _raw_notrace as Steve pointed. Thanks, - Joel 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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable 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 6B726C07542 for ; Sat, 25 May 2019 18:19:37 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E329A20815 for ; Sat, 25 May 2019 18:19:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="kkcebdla" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E329A20815 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=joelfernandes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45BBN65Fg4zDqNS for ; Sun, 26 May 2019 04:19:34 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=joelfernandes.org (client-ip=2607:f8b0:4864:20::541; helo=mail-pg1-x541.google.com; envelope-from=joel@joelfernandes.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=joelfernandes.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="kkcebdla"; dkim-atps=neutral Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45BBLp4LsQzDqKh for ; Sun, 26 May 2019 04:18:23 +1000 (AEST) Received: by mail-pg1-x541.google.com with SMTP id v9so415151pgr.13 for ; Sat, 25 May 2019 11:18:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=pwUwT3IH5HpGo/L8sP6//cCZtClp5/ip6vUnZdkkz+4=; b=kkcebdlaAxI4tg4ycJmEqrzHnyewgh+jjzD8JuWykQMD1lxIZbs14DxRaS3JzJWrkx D3zUk40qEzDf9b4/+3m3e4ZQvAeZltgNBFxxlJjzMPDywJcvPdcoFqhPgZYDwqU6gPKo ZKBP/5ISTo1G00dTfWL1Nmxp2HkYKifVw8IVU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=pwUwT3IH5HpGo/L8sP6//cCZtClp5/ip6vUnZdkkz+4=; b=YVac02ovCth1008MuHn0BCTMWoIbjcr4YNq+jJlssKKPupktZdLVZovT6szlQo9pUx nXHpPcFEap9y1F2h7cj6GS7XoD1VKqzqF+fUiFQWTG8qrS3kgn3SoSAhW24TLHGYHbr3 hfHXJoUesA0zu6d//ZVOmGeWj1Ir+GrCuMU88gKncaX/PdyeihsJ42wzrmwH5jLsT9FD ahhgDFyjHgqdr5kx/IxyTyo8NvJNjWE4l/YckiNcZ6stXePzJ4dTmDKixK12HPyFcC+g +ZYcSKfGmsDXWeRfxa42huryl1/3h8+njLQTATSakrReYePJj28oPZKRgeaWWauqX80X qdaA== X-Gm-Message-State: APjAAAUrM/KvEGgRdH2K2o9ugsDhbQbhppnqBBAGTRGrUEub2vExVh8E GVMuHiwxYRDzogFahse6NzumLw== X-Google-Smtp-Source: APXvYqx/tYCXEdllU2F4/1JetbgrhH8TFsHxXRye9Amlmvbkp4RD4ve2+88VYqD+upEJsBYYCIqDXw== X-Received: by 2002:aa7:8554:: with SMTP id y20mr121952964pfn.258.1558808300867; Sat, 25 May 2019 11:18:20 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id s24sm6537148pfe.57.2019.05.25.11.18.19 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 25 May 2019 11:18:20 -0700 (PDT) Date: Sat, 25 May 2019 14:18:18 -0400 From: Joel Fernandes To: "Paul E. McKenney" Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs Message-ID: <20190525181818.GA225569@google.com> References: <20190524234933.5133-1-joel@joelfernandes.org> <20190524232458.4bcf4eb4@gandalf.local.home> <20190525081444.GC197789@google.com> <20190525070826.16f76ee7@gandalf.local.home> <20190525141954.GA176647@google.com> <20190525155035.GE28207@linux.ibm.com> <20190525181407.GA220326@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190525181407.GA220326@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: rcu@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Lai Jiangshan , Josh Triplett , Steven Rostedt , linux-kernel@vger.kernel.org, Miguel Ojeda , Ingo Molnar , Mathieu Desnoyers , kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, May 25, 2019 at 02:14:07PM -0400, Joel Fernandes wrote: [snip] > > That aside, if we are going to change the name of an API that is > > used 160 places throughout the tree, we would need to have a pretty > > good justification. Without such a justification, it will just look > > like pointless churn to the various developers and maintainers on the > > receiving end of the patches. > > Actually, the API name change is not something I want to do, it is Steven > suggestion. My suggestion is let us just delete _raw_notrace and just use the > _raw API for tracing, since _raw doesn't do any tracing anyway. Steve pointed > that _raw_notrace does sparse checking unlike _raw, but I think that isn't an > issue since _raw doesn't do such checking at the moment anyway.. (if possible > check my cover letter again for details/motivation of this series). Come to think of it, if we/I succeed in adding lockdep checking in _raw, then we can just keep the current APIs and not delete anything. And we can have _raw_notrace skip the lockdep checks. The sparse check question would still be an open one though, since _raw doesn't do sparse checks at the moment unlike _raw_notrace as Steve pointed. Thanks, - Joel