From 7aac789885512388a66d47280d7e7777ffba1e59 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn <lee.schermerhorn@hp.com> Date: Wed, 26 May 2010 14:45:00 -0700 Subject: numa: introduce numa_mem_id()- effective local memory node id Introduce numa_mem_id(), based on generic percpu variable infrastructure to track "nearest node with memory" for archs that support memoryless nodes. Define API in <linux/topology.h> when CONFIG_HAVE_MEMORYLESS_NODES defined, else stubs. Architectures will define HAVE_MEMORYLESS_NODES if/when they support them. Archs can override definitions of: numa_mem_id() - returns node number of "local memory" node set_numa_mem() - initialize [this cpus'] per cpu variable 'numa_mem' cpu_to_mem() - return numa_mem for specified cpu; may be used as lvalue Generic initialization of 'numa_mem' occurs in __build_all_zonelists(). This will initialize the boot cpu at boot time, and all cpus on change of numa_zonelist_order, or when node or memory hot-plug requires zonelist rebuild. Archs that support memoryless nodes will need to initialize 'numa_mem' for secondary cpus as they're brought on-line. [akpm@linux-foundation.org: fix build] Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- include/linux/topology.h | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'include/linux/topology.h') diff --git a/include/linux/topology.h b/include/linux/topology.h index 2e5518f46571..c44df50a05ab 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -251,6 +251,67 @@ static inline int numa_node_id(void) #endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */ +#ifdef CONFIG_HAVE_MEMORYLESS_NODES + +/* + * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. + * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. + * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem(). + */ +DECLARE_PER_CPU(int, _numa_mem_); + +#ifndef set_numa_mem +static inline void set_numa_mem(int node) +{ + percpu_write(_numa_mem_, node); +} +#endif + +#ifndef numa_mem_id +/* Returns the number of the nearest Node with memory */ +static inline int numa_mem_id(void) +{ + return __this_cpu_read(_numa_mem_); +} +#endif + +#ifndef cpu_to_mem +static inline int cpu_to_mem(int cpu) +{ + return per_cpu(_numa_mem_, cpu); +} +#endif + +#ifndef set_cpu_numa_mem +static inline void set_cpu_numa_mem(int cpu, int node) +{ + per_cpu(_numa_mem_, cpu) = node; +} +#endif + +#else /* !CONFIG_HAVE_MEMORYLESS_NODES */ + +static inline void set_numa_mem(int node) {} + +static inline void set_cpu_numa_mem(int cpu, int node) {} + +#ifndef numa_mem_id +/* Returns the number of the nearest Node with memory */ +static inline int numa_mem_id(void) +{ + return numa_node_id(); +} +#endif + +#ifndef cpu_to_mem +static inline int cpu_to_mem(int cpu) +{ + return cpu_to_node(cpu); +} +#endif + +#endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */ + #ifndef topology_physical_package_id #define topology_physical_package_id(cpu) ((void)(cpu), -1) #endif -- cgit v1.2.3