From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Date: Tue, 28 Mar 2006 21:07:36 +0000 Subject: Re: [Patch:001/004]Unify pxm_to_node id ver.3.(generic code) Message-Id: <20060328130736.5a4273d9.akpm@osdl.org> List-Id: References: <20060328183058.CC46.Y-GOTO@jp.fujitsu.com> <20060328191250.CC48.Y-GOTO@jp.fujitsu.com> In-Reply-To: <20060328191250.CC48.Y-GOTO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yasunori Goto Cc: tony.luck@intel.com, ak@suse.de, len.brown@intel.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-ia64@vger.kernel.org, discuss@x86-64.org Yasunori Goto wrote: > > +/* Proximity bitmap length */ > +#ifdef CONFIG_NR_NODES_CHANGABLE > +#define MAX_PXM_DOMAINS CONFIG_NR_NODES > +#else > +#define MAX_PXM_DOMAINS (256) > +#endif I don't think we need CONFIG_NR_NODES_CHANGABLE (it is spelled "changeable", btw). If the architecture wants to support changing of CONFIG_NR_NODES then it can permit CONFIG_NR_NODES to be changed in its Kconfig implementation. If the architecture doesn't want to permit changing of CONFIG_NR_NODES then it should simply hardwire CONFIG_NR_NODES to the chosen value in its Kconfig. So all architectures which use acpi_numa must implement CONFIG_NR_NODES. In fact, it would probably make sense to require that all NUMA-supporting archtectures implement CONFIG_NR_NODES. Also, we already have NODES_SHIFT defined in include/asm-*/numnodes.h. What's the relationship between that and CONFIG_NR_NODES? It seems that we want to derive NODES_SHIFT from CONFIG_NR_NODES. Was ia64's CONFIG_IA64_NR_NODES the best choice? Should ia64 instead have made NODES_SHIFT Kconfigurable, and derived its max-nr_nodes from that? It's all a bit of a pickle. I guess for now a suitable approach would be to make all numa-using architectures define CONFIG_NR_NODES, and to leave that rather unpleasant-looking code in include/asm-ia64/numnodes.h as it is.