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=-7.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 92364C35646 for ; Fri, 21 Feb 2020 16:01:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63051222C4 for ; Fri, 21 Feb 2020 16:01:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582300861; bh=ITbRrKDrqN+aE+B/tpRjh8TrcZ7Qb5orGLC5oVu6KnE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=yZWHfCvlbK2Tczm1/2YgQtFFz70irnYEQ+Ve5NqisQQueEha6lt9lBUHzcXmBImDe 9sdFbcnDutMnO5j/YC2g9SXT95JdDniqOFYrMechlUZGJSIuBQDTjQRAX3pxP5MCZT bquVxkzy0DYYv/xo0Djqri8nwYUHZaWdxyDCy5WM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729128AbgBUQBA (ORCPT ); Fri, 21 Feb 2020 11:01:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:48556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728512AbgBUQA7 (ORCPT ); Fri, 21 Feb 2020 11:00:59 -0500 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (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 C2D2A2067D; Fri, 21 Feb 2020 16:00:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582300859; bh=ITbRrKDrqN+aE+B/tpRjh8TrcZ7Qb5orGLC5oVu6KnE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j41qS++6t6eNCnmNP73LXa89xPl3ZGhlzmGwSAn+v6apsDIgVNVsxCAk5yJC5c5o1 8GUvFSHY1szfuMnQNBjq0Oz4B34tzD6jsqmvfECN36Wjx7PhZlmP/BRml0MIdr0dVl v/fxsksG8/y4GOMhv7MGsEJ6MSv87uSQodi1AwsE= Date: Fri, 21 Feb 2020 16:00:54 +0000 From: Will Deacon To: Jann Horn Cc: kernel test robot , Maddie Stone , Kees Cook , "Paul E. McKenney" , Peter Zijlstra , LKML , Will Deacon , lkp@lists.01.org Subject: Re: [kernel] 247f5d7caa: will-it-scale.per_process_ops 9.6% improvement Message-ID: <20200221160053.GA19330@willie-the-truck> References: <20200221115542.GL14493@shao2-debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 21, 2020 at 04:55:42PM +0100, Jann Horn wrote: > On Fri, Feb 21, 2020 at 12:56 PM kernel test robot > wrote: > > FYI, we noticed a 9.6% improvement of will-it-scale.per_process_ops due to commit: > > > > > > commit: 247f5d7caa443d0ea5f1992aeda875e679e9bd35 ("kernel-hacking: Make DEBUG_{LIST,PLIST,SG,NOTIFIERS} non-debug options") > > https://git.kernel.org/cgit/linux/kernel/git/will/linux.git debug-list > > I'm guessing this might mean that the test bot had the DEBUG_LIST > stuff enabled in its Kconfig, whereas after the rename, the default is > used, which is off? I thought that at first, but scrolling down in the logs of the report I got totally confused by the softirqs and interrupts stuff. > This seems a bit problematic if people had DEBUG_LIST enabled in their > old kernel config and then try to reuse that config for a new kernel. > I wonder whether it'd be acceptable to keep the options under their > old names and let them "select" the new ones, or whether we have to > choose between "keep the old bad name" and "discard people's old > config flags". I can keep DEBUG_LIST kicking around and have the options default to that. Once I've finished updated lkdtm, I'll post this all out to the list. Will