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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 66BFCC10F14 for ; Thu, 10 Oct 2019 13:50:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C08721D71 for ; Thu, 10 Oct 2019 13:50:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726068AbfJJNuz (ORCPT ); Thu, 10 Oct 2019 09:50:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:43396 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725932AbfJJNuz (ORCPT ); Thu, 10 Oct 2019 09:50:55 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 456AE2067B; Thu, 10 Oct 2019 13:43:55 +0000 (UTC) Date: Thu, 10 Oct 2019 09:43:52 -0400 From: Steven Rostedt To: Miroslav Benes Cc: Petr Mladek , jikos@kernel.org, Joe Lawrence , jpoimboe@redhat.com, mingo@redhat.com, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org Subject: Re: [PATCH 0/3] ftrace: Introduce PERMANENT ftrace_ops flag Message-ID: <20191010094352.35056c84@gandalf.local.home> In-Reply-To: References: <20191007081714.20259-1-mbenes@suse.cz> <20191008193534.GA16675@redhat.com> <20191009112234.bi7lvp4pvmna26vz@pathway.suse.cz> <20191009102654.501ad7c3@gandalf.local.home> <20191010085035.emsdks6xecazqc6k@pathway.suse.cz> <20191010091403.5ecf0fdb@gandalf.local.home> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: live-patching-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On Thu, 10 Oct 2019 15:38:20 +0200 (CEST) Miroslav Benes wrote: > On Thu, 10 Oct 2019, Steven Rostedt wrote: > > > On Thu, 10 Oct 2019 10:50:35 +0200 > > Petr Mladek wrote: > > > > > It will make the flag unusable for other ftrace users. But it > > > will be already be the case when it can't be disabled. > > > > Honestly, I hate that flag. Most people don't even know about it. It > > was added in the beginning of ftrace as a way to stop function tracing > > in the latency tracer. But that use case has been obsoleted by > > 328df4759c03e ("tracing: Add function-trace option to disable function > > tracing of latency tracers"). I may just remove the damn thing and only > > add it back if somebody complains about it. > > That would of course solve the issue too and code removal is always > better. > Yes, but let's still add the patch that does the permanent check. And then I'll put the "remove this flag" patch on top (and revert everything else). This way, if somebody complains, and Linus reverts the removal patch, we don't end up breaking live kernel patching again ;-) -- Steve