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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E20DAC25B50 for ; Mon, 23 Jan 2023 17:45:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230489AbjAWRpt (ORCPT ); Mon, 23 Jan 2023 12:45:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229791AbjAWRps (ORCPT ); Mon, 23 Jan 2023 12:45:48 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F27D91E5FD; Mon, 23 Jan 2023 09:45:44 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 58C02C14; Mon, 23 Jan 2023 09:46:26 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.12.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C14F23F71E; Mon, 23 Jan 2023 09:45:43 -0800 (PST) Date: Mon, 23 Jan 2023 17:45:41 +0000 From: Mark Rutland To: Steven Rostedt Cc: LKML , Linux Trace Kernel , Masami Hiramatsu Subject: Re: [PATCH] ftrace/scripts: Update the instructions for ftrace-bisect.sh Message-ID: References: <20230123112252.022003dd@gandalf.local.home> <20230123121147.341b0992@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230123121147.341b0992@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Mon, Jan 23, 2023 at 12:11:47PM -0500, Steven Rostedt wrote: > On Mon, 23 Jan 2023 16:59:55 +0000 > Mark Rutland wrote: > > > > +# The old (slow) way, for kernels before v5.1. > > > +# > > > +# [old-way] # cat available_filter_functions > ~/full-file > > > +# > > > +# [old-way] *** Note *** this will take several minutes. Setting multiple > > > +# [old-way] functions is an O(n^2) operation, and we are dealing with thousands > > > +# [old-way] of functions. So go have coffee, talk with your coworkers, read > > > +# [old-way] facebook. And eventually, this operation will end. > > > > Super-trivial nit, but the above step isn't actually that expensive, and it's > > the subsequent write to set_ftrace_filter that's going to be slow. > > How about: > > "*** Note *** this process will take several minutes to update the filters." Sounds good to me! :) FWIW, with that: Acked-by: Mark Rutland > > That double spacing in 'go have coffee' looks odd; is that an old error from > > reformatting a line break, and/or a missing 'a' ? > > I can fix that. Thanks! > > How about: > > > > # [old-way] *** Note *** writing function names to set_ftrace_filter will take > > # [old-way] several minutes. Setting multiple functions is an O(n^2) operation, > > # [old-way] and we will set thousands of functions. So for subsequent steps, > > # [old-way] go have a coffee, talk with your coworkers, read facebook. And > > # [old-way] eventually, this operation will end. > > > > ... or leave this in place below, and add "If using [old-way] ..." to the start? > > I wanted to explicitly show that the above is only a reference to the old > way, and leave no doubt about it. It was either doing this or deleting it > completely. I chose to keep it. Fair enough! Mark.