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 10E09C761AF for ; Thu, 23 Mar 2023 10:16:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231151AbjCWKQj (ORCPT ); Thu, 23 Mar 2023 06:16:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231444AbjCWKQJ (ORCPT ); Thu, 23 Mar 2023 06:16:09 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B38B21CF74; Thu, 23 Mar 2023 03:15:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E6318625AC; Thu, 23 Mar 2023 10:15:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B040BC4339C; Thu, 23 Mar 2023 10:15:36 +0000 (UTC) Date: Thu, 23 Mar 2023 10:15:33 +0000 From: Catalin Marinas To: Mike Rapoport Cc: Andrew Morton , Arnd Bergmann , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Geert Uytterhoeven , Guo Ren , John Paul Adrian Glaubitz , "Kirill A. Shutemov" , Max Filippov , Michael Ellerman , Rich Felker , Russell King , Will Deacon , Yoshinori Sato , Zi Yan , linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org Subject: Re: [PATCH 02/14] arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER Message-ID: References: <20230323092156.2545741-1-rppt@kernel.org> <20230323092156.2545741-3-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230323092156.2545741-3-rppt@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 23, 2023 at 11:21:44AM +0200, Mike Rapoport wrote: > From: "Mike Rapoport (IBM)" > > It is not a good idea to change fundamental parameters of core memory > management. Having predefined ranges suggests that the values within > those ranges are sensible, but one has to *really* understand > implications of changing MAX_ORDER before actually amending it and > ranges don't help here. > > Drop ranges in definition of ARCH_FORCE_MAX_ORDER > > Signed-off-by: Mike Rapoport (IBM) > --- > arch/arm64/Kconfig | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index e60baf7859d1..bab6483e4317 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1489,9 +1489,7 @@ config XEN > config ARCH_FORCE_MAX_ORDER > int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES > default "13" if ARM64_64K_PAGES > - range 11 13 if ARM64_16K_PAGES > default "11" if ARM64_16K_PAGES > - range 10 15 if ARM64_4K_PAGES > default "10" I don't mind rewriting the help text as in the subsequent patch but I'd keep the ranges as a safety measure. It's less wasted time explaining to people why some random max order doesn't work. Alternatively, we can drop the ranges but make this option configurable only if EXPERT. -- Catalin