From 34b71f1e04fcba578e719e675b4882eeeb2a1f6f Mon Sep 17 00:00:00 2001 From: Tang Chen Date: Fri, 22 Feb 2013 16:33:37 -0800 Subject: [PATCH] page_alloc: add movable_memmap kernel parameter Add functions to parse movablemem_map boot option. Since the option could be specified more then once, all the maps will be stored in the global variable movablemem_map.map array. And also, we keep the array in monotonic increasing order by start_pfn. And merge all overlapped ranges. [akpm@linux-foundation.org: improve comment] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: remove unneeded parens] Signed-off-by: Tang Chen Signed-off-by: Lai Jiangshan Reviewed-by: Wen Congyang Tested-by: Lin Feng Cc: Wu Jianguo Cc: Mel Gorman Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 17 ++++ include/linux/mm.h | 11 +++ mm/page_alloc.c | 131 ++++++++++++++++++++++++++++ 3 files changed, 159 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9aa8ff3e54dc..722a74161246 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1640,6 +1640,23 @@ bytes respectively. Such letter suffixes can also be entirely omitted. that the amount of memory usable for all allocations is not too small. + movablemem_map=nn[KMG]@ss[KMG] + [KNL,X86,IA-64,PPC] This parameter is similar to + memmap except it specifies the memory map of + ZONE_MOVABLE. + If more areas are all within one node, then from + lowest ss to the end of the node will be ZONE_MOVABLE. + If an area covers two or more nodes, the area from + ss to the end of the 1st node will be ZONE_MOVABLE, + and all the rest nodes will only have ZONE_MOVABLE. + If memmap is specified at the same time, the + movablemem_map will be limited within the memmap + areas. If kernelcore or movablecore is also specified, + movablemem_map will have higher priority to be + satisfied. So the administrator should be careful that + the amount of movablemem_map areas are not too large. + Otherwise kernel won't have enough memory to start. + MTD_Partition= [MTD] Format: ,,, diff --git a/include/linux/mm.h b/include/linux/mm.h index 9d659491c0ae..ce9bd3049836 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1359,6 +1359,17 @@ extern void free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn); extern void sparse_memory_present_with_active_regions(int nid); +#define MOVABLEMEM_MAP_MAX MAX_NUMNODES +struct movablemem_entry { + unsigned long start_pfn; /* start pfn of memory segment */ + unsigned long end_pfn; /* end pfn of memory segment (exclusive) */ +}; + +struct movablemem_map { + int nr_map; + struct movablemem_entry map[MOVABLEMEM_MAP_MAX]; +}; + #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ #if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 703944809666..aa1cc5fe9904 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -202,6 +202,9 @@ static unsigned long __meminitdata nr_all_pages; static unsigned long __meminitdata dma_reserve; #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP +/* Movable memory ranges, will also be used by memblock subsystem. */ +struct movablemem_map movablemem_map; + static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; static unsigned long __initdata required_kernelcore; @@ -5078,6 +5081,134 @@ static int __init cmdline_parse_movablecore(char *p) early_param("kernelcore", cmdline_parse_kernelcore); early_param("movablecore", cmdline_parse_movablecore); +/** + * insert_movablemem_map - Insert a memory range in to movablemem_map.map. + * @start_pfn: start pfn of the range + * @end_pfn: end pfn of the range + * + * This function will also merge the overlapped ranges, and sort the array + * by start_pfn in monotonic increasing order. + */ +static void __init insert_movablemem_map(unsigned long start_pfn, + unsigned long end_pfn) +{ + int pos, overlap; + + /* + * pos will be at the 1st overlapped range, or the position + * where the element should be inserted. + */ + for (pos = 0; pos < movablemem_map.nr_map; pos++) + if (start_pfn <= movablemem_map.map[pos].end_pfn) + break; + + /* If there is no overlapped range, just insert the element. */ + if (pos == movablemem_map.nr_map || + end_pfn < movablemem_map.map[pos].start_pfn) { + /* + * If pos is not the end of array, we need to move all + * the rest elements backward. + */ + if (pos < movablemem_map.nr_map) + memmove(&movablemem_map.map[pos+1], + &movablemem_map.map[pos], + sizeof(struct movablemem_entry) * + (movablemem_map.nr_map - pos)); + movablemem_map.map[pos].start_pfn = start_pfn; + movablemem_map.map[pos].end_pfn = end_pfn; + movablemem_map.nr_map++; + return; + } + + /* overlap will be at the last overlapped range */ + for (overlap = pos + 1; overlap < movablemem_map.nr_map; overlap++) + if (end_pfn < movablemem_map.map[overlap].start_pfn) + break; + + /* + * If there are more ranges overlapped, we need to merge them, + * and move the rest elements forward. + */ + overlap--; + movablemem_map.map[pos].start_pfn = min(start_pfn, + movablemem_map.map[pos].start_pfn); + movablemem_map.map[pos].end_pfn = max(end_pfn, + movablemem_map.map[overlap].end_pfn); + + if (pos != overlap && overlap + 1 != movablemem_map.nr_map) + memmove(&movablemem_map.map[pos+1], + &movablemem_map.map[overlap+1], + sizeof(struct movablemem_entry) * + (movablemem_map.nr_map - overlap - 1)); + + movablemem_map.nr_map -= overlap - pos; +} + +/** + * movablemem_map_add_region - Add a memory range into movablemem_map. + * @start: physical start address of range + * @end: physical end address of range + * + * This function transform the physical address into pfn, and then add the + * range into movablemem_map by calling insert_movablemem_map(). + */ +static void __init movablemem_map_add_region(u64 start, u64 size) +{ + unsigned long start_pfn, end_pfn; + + /* In case size == 0 or start + size overflows */ + if (start + size <= start) + return; + + if (movablemem_map.nr_map >= ARRAY_SIZE(movablemem_map.map)) { + pr_err("movablemem_map: too many entries;" + " ignoring [mem %#010llx-%#010llx]\n", + (unsigned long long) start, + (unsigned long long) (start + size - 1)); + return; + } + + start_pfn = PFN_DOWN(start); + end_pfn = PFN_UP(start + size); + insert_movablemem_map(start_pfn, end_pfn); +} + +/* + * cmdline_parse_movablemem_map - Parse boot option movablemem_map. + * @p: The boot option of the following format: + * movablemem_map=nn[KMG]@ss[KMG] + * + * This option sets the memory range [ss, ss+nn) to be used as movable memory. + * + * Return: 0 on success or -EINVAL on failure. + */ +static int __init cmdline_parse_movablemem_map(char *p) +{ + char *oldp; + u64 start_at, mem_size; + + if (!p) + goto err; + + oldp = p; + mem_size = memparse(p, &p); + if (p == oldp) + goto err; + + if (*p == '@') { + oldp = ++p; + start_at = memparse(p, &p); + if (p == oldp || *p != '\0') + goto err; + + movablemem_map_add_region(start_at, mem_size); + return 0; + } +err: + return -EINVAL; +} +early_param("movablemem_map", cmdline_parse_movablemem_map); + #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ /**