From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by kanga.kvack.org (Postfix) with ESMTP id 763116B0003 for ; Thu, 11 Oct 2018 14:46:05 -0400 (EDT) Received: by mail-io1-f70.google.com with SMTP id l24-v6so8741807iok.21 for ; Thu, 11 Oct 2018 11:46:05 -0700 (PDT) Received: from ale.deltatee.com (ale.deltatee.com. [207.54.116.67]) by mx.google.com with ESMTPS id o21-v6si20626037jad.76.2018.10.11.11.46.04 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 11 Oct 2018 11:46:04 -0700 (PDT) From: Logan Gunthorpe References: <20181005161642.2462-1-logang@deltatee.com> <20181005161642.2462-6-logang@deltatee.com> <20181011133730.GB7276@lst.de> <8cea5ffa-5fbf-8ea2-b673-20e2d09a910d@deltatee.com> Message-ID: <83cfd2d7-b840-b0c6-594e-8b39be8177c1@deltatee.com> Date: Thu, 11 Oct 2018 12:45:56 -0600 MIME-Version: 1.0 In-Reply-To: <8cea5ffa-5fbf-8ea2-b673-20e2d09a910d@deltatee.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 7bit Subject: Re: [PATCH 5/5] RISC-V: Implement sparsemem Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Rob Herring , Albert Ou , Andrew Waterman , linux-sh@vger.kernel.org, Palmer Dabbelt , linux-kernel@vger.kernel.org, Stephen Bates , Zong Li , linux-mm@kvack.org, Olof Johansson , linux-riscv@lists.infradead.org, Michael Clark , linux-arm-kernel@lists.infradead.org On 2018-10-11 10:24 a.m., Logan Gunthorpe wrote: > > > On 2018-10-11 7:37 a.m., Christoph Hellwig wrote: >>> +/* >>> + * Log2 of the upper bound of the size of a struct page. Used for sizing >>> + * the vmemmap region only, does not affect actual memory footprint. >>> + * We don't use sizeof(struct page) directly since taking its size here >>> + * requires its definition to be available at this point in the inclusion >>> + * chain, and it may not be a power of 2 in the first place. >>> + */ >>> +#define STRUCT_PAGE_MAX_SHIFT 6 >> >> I know this is copied from arm64, but wouldn't this be a good time >> to move this next to the struct page defintion? Ok, I spoke too soon... Having this define next to the struct page definition works great for riscv. However, making that happen in arm64 seems to be a nightmare. The include chain in arm64 is tangled up so much that including mm_types where this is needed seems to be extremely difficult. Unless you have any ideas, this might not be possible. Logan