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=-1.0 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 E47B7C43219 for ; Mon, 29 Apr 2019 19:07:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B6C3520675 for ; Mon, 29 Apr 2019 19:07:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729125AbfD2TH3 (ORCPT ); Mon, 29 Apr 2019 15:07:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:58960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726725AbfD2TH3 (ORCPT ); Mon, 29 Apr 2019 15:07:29 -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 2FFAD20673; Mon, 29 Apr 2019 19:07:26 +0000 (UTC) Date: Mon, 29 Apr 2019 15:07:24 -0400 From: Steven Rostedt To: Linus Torvalds Cc: Peter Zijlstra , Nicolai Stange , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "the arch/x86 maintainers" , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , Shuah Khan , Konrad Rzeszutek Wilk , Tim Chen , Sebastian Andrzej Siewior , Mimi Zohar , Juergen Gross , Nick Desaulniers , Nayna Jain , Masahiro Yamada , Andy Lutomirski , Joerg Roedel , Linux List Kernel Mailing , live-patching@vger.kernel.org, "open list:KERNEL SELFTEST FRAMEWORK" Subject: Re: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Message-ID: <20190429150724.6e501d27@gandalf.local.home> In-Reply-To: References: <20190427100639.15074-1-nstange@suse.de> <20190427100639.15074-4-nstange@suse.de> <20190427102657.GF2623@hirez.programming.kicks-ass.net> <20190428133826.3e142cfd@oasis.local.home> <20190429145250.1a5da6ed@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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 29 Apr 2019 11:59:04 -0700 Linus Torvalds wrote: > I really don't care. Just do what I suggested, and if you have numbers to > show problems, then maybe I'll care. > Are you suggesting that I rewrite the code to do it one function at a time? This has always been batch mode. This is not something new. The function tracer has been around longer than the text poke code. > Right now you're just making excuses for this. I described the solution > months ago, now I've written a patch, if that's not good enough then we can > just skip this all entirely. > > Honestly, if you need to rewrite tens of thousands of calls, maybe you're > doing something wrong? > # cd /sys/kernel/debug/tracing # cat available_filter_functions | wc -l 45856 # cat enabled_functions | wc -l 0 # echo function > current_tracer # cat enabled_functions | wc -l 45856 There, I just enabled 45,856 function call sites in one shot! How else do you want to update them? Every function in the kernel has a nop, that turns into a call to the ftrace_handler, if I add another user of that code, it will change each one as well. -- Steve