From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 26 May 2020 18:11:59 +0100 From: Catalin Marinas Subject: Re: [PATCH v2 03/20] mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option 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-Disposition: inline In-Reply-To: <20200429121126.17989-4-rppt@kernel.org> To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, Andrew Morton , Baoquan He , Brian Cain , "David S. Miller" , Geert Uytterhoeven , Greentime Hu , Greg Ungerer , Guan Xuetao , Guo Ren , Heiko Carstens , Helge Deller , Hoan Tran , "James E.J. Bottomley" , Jonathan Corbet , Ley Foon Tan , Mark Salter , Matt Turner , Max Filippov , Michael Ellerman , Michal Hocko , Michal Simek , Nick Hu , Paul Walmsley , Qian Cai , Richard Weinberger , Rich Felker , Russell King , Stafford Horne , Thomas Bogendoerfer , Tony Luck , Vineet Gupta , x86@kernel.org, Yoshinori Sato , linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, openrisc@lists.librecores.org, sparclinux@vger.kernel.org, uclinux-h8-devel@lists.sourceforge.jp, Mike Rapoport List-ID: 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