From 93b7504e3e6c1d98586854806e51bea329ea3aa9 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Thu, 23 Jun 2005 00:07:47 -0700 Subject: [PATCH] [PATCH] Introduce new Kconfig option for NUMA or DISCONTIG There is some confusion that arose when working on SPARSEMEM patch between what is needed for DISCONTIG vs. NUMA. Multiple pg_data_t's are needed for DISCONTIGMEM or NUMA, independently. All of the current NUMA implementations require an implementation of DISCONTIG. Because of this, quite a lot of code which is really needed for NUMA is actually under DISCONTIG #ifdefs. For SPARSEMEM, we changed some of these #ifdefs to CONFIG_NUMA, but that broke the DISCONTIG=y and NUMA=n case. Introducing this new NEED_MULTIPLE_NODES config option allows code that is needed for both NUMA or DISCONTIG to be separated out from code that is specific to DISCONTIG. One great advantage of this approach is that it doesn't require every architecture to be converted over. All of the current implementations should "just work", only the ones implementing SPARSEMEM will have to be fixed up. The change to free_area_init() makes it work inside, or out of the new config option. Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 6 +++--- mm/Kconfig | 8 ++++++++ mm/page_alloc.c | 6 +++--- 3 files changed, 14 insertions(+), 6 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 39e912708e2..95f4a780ea6 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -402,7 +402,7 @@ int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *, /* Returns the number of the current Node. */ #define numa_node_id() (cpu_to_node(raw_smp_processor_id())) -#ifndef CONFIG_DISCONTIGMEM +#ifndef CONFIG_NEED_MULTIPLE_NODES extern struct pglist_data contig_page_data; #define NODE_DATA(nid) (&contig_page_data) @@ -410,11 +410,11 @@ extern struct pglist_data contig_page_data; #define MAX_NODES_SHIFT 1 #define pfn_to_nid(pfn) (0) -#else /* CONFIG_DISCONTIGMEM */ +#else /* CONFIG_NEED_MULTIPLE_NODES */ #include -#endif /* !CONFIG_DISCONTIGMEM */ +#endif /* !CONFIG_NEED_MULTIPLE_NODES */ #if BITS_PER_LONG == 32 || defined(ARCH_HAS_ATOMIC_UNSIGNED) /* diff --git a/mm/Kconfig b/mm/Kconfig index 69caa9d8674..15c13139363 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -23,3 +23,11 @@ config DISCONTIGMEM endchoice +# +# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's +# to represent different areas of memory. This variable allows +# those dependencies to exist individually. +# +config NEED_MULTIPLE_NODES + def_bool y + depends on DISCONTIGMEM || NUMA diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1958358e29b..20e239599db 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1972,18 +1972,18 @@ void __init free_area_init_node(int nid, struct pglist_data *pgdat, free_area_init_core(pgdat, zones_size, zholes_size); } -#ifndef CONFIG_DISCONTIGMEM +#ifndef CONFIG_NEED_MULTIPLE_NODES static bootmem_data_t contig_bootmem_data; struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; EXPORT_SYMBOL(contig_page_data); +#endif void __init free_area_init(unsigned long *zones_size) { - free_area_init_node(0, &contig_page_data, zones_size, + free_area_init_node(0, NODE_DATA(0), zones_size, __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); } -#endif #ifdef CONFIG_PROC_FS -- 2.41.1