From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: [PATCH v2 03/20] mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option Date: Tue, 26 May 2020 18:11:59 +0100 Message-ID: <20200526171159.GJ17051@gaia> References: <20200429121126.17989-1-rppt@kernel.org> <20200429121126.17989-4-rppt@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20200429121126.17989-4-rppt@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+gla-linux-snps-arc=m.gmane-mx.org@lists.infradead.org To: Mike Rapoport Cc: Rich Felker , linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, Heiko Carstens , Michal Hocko , "James E.J. Bottomley" , Max Filippov , Guo Ren , linux-csky@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, Mike Rapoport , Greg Ungerer , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-c6x-dev@linux-c6x.org, Baoquan He , Jonathan Corbet , linux-sh@vger.kernel.org, Michael Ellerman , Helge Deller , x86@kernel.org, Russell King , Ley Foon Tan List-Id: linux-arch.vger.kernel.org On Wed, Apr 29, 2020 at 03:11:09PM +0300, Mike Rapoport wrote: > From: Mike Rapoport > > The CONFIG_HAVE_MEMBLOCK_NODE_MAP is used to differentiate initialization > of nodes and zones structures between the systems that have region to node > mapping in memblock and those that don't. > > Currently all the NUMA architectures enable this option and for the > non-NUMA systems we can presume that all the memory belongs to node 0 and > therefore the compile time configuration option is not required. > > The remaining few architectures that use DISCONTIGMEM without NUMA are > easily updated to use memblock_add_node() instead of memblock_add() and > thus have proper correspondence of memblock regions to NUMA nodes. > > Still, free_area_init_node() must have a backward compatible version > because its semantics with and without CONFIG_HAVE_MEMBLOCK_NODE_MAP is > different. Once all the architectures will use the new semantics, the > entire compatibility layer can be dropped. > > To avoid addition of extra run time memory to store node id for > architectures that keep memblock but have only a single node, the node id > field of the memblock_region is guarded by CONFIG_NEED_MULTIPLE_NODES and > the corresponding accessors presume that in those cases it is always 0. > > Signed-off-by: Mike Rapoport > --- > .../vm/numa-memblock/arch-support.txt | 34 ------ > arch/alpha/mm/numa.c | 4 +- > arch/arm64/Kconfig | 1 - For arm64: Acked-by: Catalin Marinas