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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 466C8C11F69 for ; Fri, 2 Jul 2021 13:11:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AB6C6141D for ; Fri, 2 Jul 2021 13:11:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232215AbhGBNNr (ORCPT ); Fri, 2 Jul 2021 09:13:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:43236 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230481AbhGBNNp (ORCPT ); Fri, 2 Jul 2021 09:13:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 167E3613B1; Fri, 2 Jul 2021 13:11:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625231473; bh=VTOEMFLCdkiosprAyMGyX32cPkmxfgkO4zvLSKjrATU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FrMCSVMH62c/ElTMpje1nVPi0IB9kFdzijtpw/IWTCM8LK6e2a06g17PKQsOVIhU4 xmLFfpbF4eEbEJbRdTEdvxacBz2d//2/GdiVTDHjBpDreEhC5Y/xuPW6AGIyek+ozQ FF4MgLEu33racYiy2TZoXV/acUHG0dFUIi0rwyjh8q1029TNvoHc6emvI1OuwtTi/M CEbZ9ErgwsW9aGiW4wSx+XiHF8M4uQFs/X8CL3bAU7mjiHbLufEm1fyPbzvBXFR3Ir k9tPHmohsr6M2GGeDpBfBHUxANVAwLnoNl8wUsZrEsvi1HGL5ZLN3f/1DdWrpFTAW2 gs6sV9d6JVfjQ== Date: Fri, 2 Jul 2021 16:11:06 +0300 From: Mike Rapoport To: Miles Chen Cc: Andrew Morton , Mark Rutland , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com Subject: Re: [PATCH] mm/sparse: clarify pgdat_to_phys Message-ID: References: <20210630092309.17654-1-miles.chen@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210630092309.17654-1-miles.chen@mediatek.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 30, 2021 at 05:23:09PM +0800, Miles Chen wrote: > clarify pgdat_to_phys() by wrapping pgdat_to_phys > with CONFIG_NUMA. (the same config as contig_page_data) > > No functional change intended. > > Comment from Mark [1]: > " > ... and I reckon it'd be clearer and more robust to define > pgdat_to_phys() in the same ifdefs as contig_page_data so > that these, stay in-sync. e.g. have: > > | #ifdef CONFIG_NUMA > | #define pgdat_to_phys(x) virt_to_phys(x) > | #else /* CONFIG_NUMA */ > | > | extern struct pglist_data contig_page_data; > | ... > | #define pgdat_to_phys(x) __pa_symbol(&contig_page_data) > | > | #endif /* CONIFIG_NUMA */ > " > > [1] https://lore.kernel.org/linux-arm-kernel/20210615131902.GB47121@C02TD0UTHF1T.local/ > > Cc: Mark Rutland > Signed-off-by: Miles Chen > --- > mm/sparse.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/mm/sparse.c b/mm/sparse.c > index 7272f7a1449d..62c21ec28e33 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -344,14 +344,15 @@ size_t mem_section_usage_size(void) > return sizeof(struct mem_section_usage) + usemap_size(); > } > > -static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat) > -{ > -#ifndef CONFIG_NUMA > - return __pa_symbol(pgdat); > -#else > - return __pa(pgdat); > -#endif > -} > +#ifdef CONFIG_NUMA > +#define pgdat_to_phys(pgdat) __pa(pgdat) > +#else /* CONFIG_NUMA */ > +/* > + * When !CONFIG_NUMA, we only expect pgdat == &contig_page_data, > + * and use __pa_symbol(). > + */ > +#define pgdat_to_phys(pgdat) __pa_symbol(pgdat) > +#endif /* CONFIG_NUMA */ I'm not sure a macro is better than a static inline. Maybe we'd want to warn if pgdat passed to pgtat_to_phys() is not &contig_page_data, e.g something like static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat) { if (!IS_ENABLED(CONFIG_NUMA)) { if (pgdat == &contig_page_data) return __pa_symbol(&contig_page_data); else pr_warn("Unexpected pglist_data pointer!\n"); } return __pa(pgdat); } > #ifdef CONFIG_MEMORY_HOTREMOVE > static struct mem_section_usage * __init > -- > 2.18.0 > -- Sincerely yours, Mike.