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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 BBE97C433FF for ; Wed, 14 Aug 2019 14:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 87F5A2084F for ; Wed, 14 Aug 2019 14:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565791576; bh=4eams4JAN8LU22oNBMVq1KJESop20sHz+BP5igsQz7U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=g/of5ZGS8h9AjkafJF3/seWMYQzU7SeQXO2pLxMqIQzh7BY/7JXRgWld9SYbfuzI+ Vsph5KF+JlxQMlDeWq4KTtva9SU7vKRxgHz3IV769HsWeeQ6OMmNOWeFyHQxFXTOFf Pb7snl8EAFdFCPz3xRO8KQHBh/DjLaUjWtyAdaEk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727965AbfHNOGK (ORCPT ); Wed, 14 Aug 2019 10:06:10 -0400 Received: from mx2.suse.de ([195.135.220.15]:57086 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726951AbfHNOGK (ORCPT ); Wed, 14 Aug 2019 10:06:10 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 28850AFA9; Wed, 14 Aug 2019 14:06:09 +0000 (UTC) Date: Wed, 14 Aug 2019 16:06:08 +0200 From: Michal Hocko To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dan Williams , Borislav Petkov , Andrew Morton , Bjorn Helgaas , Ingo Molnar , Dave Hansen , Nadav Amit , Wei Yang , Oscar Salvador Subject: Re: [PATCH v1 1/4] resource: Use PFN_UP / PFN_DOWN in walk_system_ram_range() Message-ID: <20190814140608.GZ17933@dhcp22.suse.cz> References: <20190809125701.3316-1-david@redhat.com> <20190809125701.3316-2-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190809125701.3316-2-david@redhat.com> 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 09-08-19 14:56:58, David Hildenbrand wrote: > This makes it clearer that we will never call func() with duplicate PFNs > in case we have multiple sub-page memory resources. All unaligned parts > of PFNs are completely discarded. > > Cc: Dan Williams > Cc: Borislav Petkov > Cc: Andrew Morton > Cc: Bjorn Helgaas > Cc: Ingo Molnar > Cc: Dave Hansen > Cc: Nadav Amit > Cc: Wei Yang > Cc: Oscar Salvador > Signed-off-by: David Hildenbrand Acked-by: Michal Hocko > --- > kernel/resource.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/resource.c b/kernel/resource.c > index 7ea4306503c5..88ee39fa9103 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -487,8 +487,8 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, > while (start < end && > !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, > false, &res)) { > - pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT; > - end_pfn = (res.end + 1) >> PAGE_SHIFT; > + pfn = PFN_UP(res.start); > + end_pfn = PFN_DOWN(res.end + 1); > if (end_pfn > pfn) > ret = (*func)(pfn, end_pfn - pfn, arg); > if (ret) > -- > 2.21.0 -- Michal Hocko SUSE Labs