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 C32607D2EF for ; Sat, 25 May 2019 14:19:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727004AbfEYOT5 (ORCPT ); Sat, 25 May 2019 10:19:57 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:35486 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726947AbfEYOT5 (ORCPT ); Sat, 25 May 2019 10:19:57 -0400 Received: by mail-pl1-f196.google.com with SMTP id p1so5329740plo.2 for ; Sat, 25 May 2019 07:19:56 -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=oA6FcJ72zNid4SwAO5Y6rnUXHdUQj0L4tCh0ZCLJSFI=; b=NX/KmtDCs4EGb9mO5SMMkYszAarGd0UZP0S8vAwwQjy5ElvPnArSQCM79p6zDDG599 0Nrwt8GmeJlUpxdahkhFUQgjljvJWEl8W0oRgaWVvzii8pMGxtDBNNez3szb6V5hR7Sl /oVTbrXCcQaK/wd3nTy2BIpckmRhnlhqmFMt8= 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=oA6FcJ72zNid4SwAO5Y6rnUXHdUQj0L4tCh0ZCLJSFI=; b=mCxj8KbziTYYvtVzjAYp/nbKlo6gGAdRnKZEjLjv0WEYjlVs9he96/lsaOlk5AKQaI WPKXXeQGMTDPazzR3zvmIv5Eu0DI8sjnXdd7xUcUGWI/3CHj4dqqLod9S7PZa+n0rckR /JjgEPL9PA25Rl9XLTW0DYqZm2mGSD/S43OJABoyTCqZTdexEOi7iYgskJ9lMjeeIPxz IoSFyWsG0ySEBVYJvjKirV2Ie4xTPJncs9SRhP350S1kxJg9xXjV/b+AIKAF5NOK6vTz 7hrcMtURJ/yqXIYAydmwaU8CFG7l4WzpIlpJCTk7aKtfi/e2xfaoBDaU6M11GsCg7HhD EVMw== X-Gm-Message-State: APjAAAWTaAbmolVMSUITgyi3XQZrYEMY5wwWXllJpkh/1ynEWfR4igNo /KXO5P6v2QlfG3pTuBURnxpaeg== X-Google-Smtp-Source: APXvYqz1DtDvRXpDvMqOaGFx8+a+/FEFbXY2Ry7LB+HHkerKQ+Avr2mpCrR118QII1Whv7IzQ6nqfw== X-Received: by 2002:a17:902:6bcb:: with SMTP id m11mr42398103plt.318.1558793996314; Sat, 25 May 2019 07:19:56 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id p63sm6795234pfb.70.2019.05.25.07.19.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 25 May 2019 07:19:55 -0700 (PDT) Date: Sat, 25 May 2019 10:19:54 -0400 From: Joel Fernandes To: Steven Rostedt Cc: 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 E. McKenney" , Paul Mackerras , rcu@vger.kernel.org Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs Message-ID: <20190525141954.GA176647@google.com> References: <20190524234933.5133-1-joel@joelfernandes.org> <20190524232458.4bcf4eb4@gandalf.local.home> <20190525081444.GC197789@google.com> <20190525070826.16f76ee7@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190525070826.16f76ee7@gandalf.local.home> 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 07:08:26AM -0400, Steven Rostedt wrote: > On Sat, 25 May 2019 04:14:44 -0400 > Joel Fernandes wrote: > > > > I guess the difference between the _raw_notrace and just _raw variants > > > is that _notrace ones do a rcu_check_sparse(). Don't we want to keep > > > that check? > > > > This is true. > > > > Since the users of _raw_notrace are very few, is it worth keeping this API > > just for sparse checking? The API naming is also confusing. I was expecting > > _raw_notrace to do fewer checks than _raw, instead of more. Honestly, I just > > want to nuke _raw_notrace as done in this series and later we can introduce a > > sparse checking version of _raw if need-be. The other option could be to > > always do sparse checking for _raw however that used to be the case and got > > changed in http://lists.infradead.org/pipermail/linux-afs/2016-July/001016.html > > What if we just rename _raw to _raw_nocheck, and _raw_notrace to _raw ? That would also mean changing 160 usages of _raw to _raw_nocheck in the kernel :-/. The tracing usage of _raw_notrace is only like 2 or 3 users. Can we just call rcu_check_sparse directly in the calling code for those and eliminate the APIs? I wonder what Paul thinks about the matter as well. thanks, Steven!