diff options
Diffstat (limited to 'mm/memblock.c')
| -rw-r--r-- | mm/memblock.c | 124 |
1 files changed, 111 insertions, 13 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index 0ac412a..53e477b 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -20,6 +20,8 @@ #include <linux/seq_file.h> #include <linux/memblock.h> +#include <asm-generic/sections.h> + static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock; static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock; @@ -32,6 +34,7 @@ struct memblock memblock __initdata_memblock = { .reserved.cnt = 1, /* empty dummy entry */ .reserved.max = INIT_MEMBLOCK_REGIONS, + .bottom_up = false, .current_limit = MEMBLOCK_ALLOC_ANYWHERE, }; @@ -82,6 +85,73 @@ static long __init_memblock memblock_overlaps_region(struct memblock_type *type, return (i < type->cnt) ? i : -1; } +/* + * __memblock_find_range_bottom_up - find free area utility in bottom-up + * @start: start of candidate range + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} + * @size: size of free area to find + * @align: alignment of free area to find + * @nid: nid of the free area to find, %MAX_NUMNODES for any node + * + * Utility called from memblock_find_in_range_node(), find free area bottom-up. + * + * RETURNS: + * Found address on success, 0 on failure. + */ +static phys_addr_t __init_memblock +__memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end, + phys_addr_t size, phys_addr_t align, int nid) +{ + phys_addr_t this_start, this_end, cand; + u64 i; + + for_each_free_mem_range(i, nid, &this_start, &this_end, NULL) { + this_start = clamp(this_start, start, end); + this_end = clamp(this_end, start, end); + + cand = round_up(this_start, align); + if (cand < this_end && this_end - cand >= size) + return cand; + } + + return 0; +} + +/** + * __memblock_find_range_top_down - find free area utility, in top-down + * @start: start of candidate range + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} + * @size: size of free area to find + * @align: alignment of free area to find + * @nid: nid of the free area to find, %MAX_NUMNODES for any node + * + * Utility called from memblock_find_in_range_node(), find free area top-down. + * + * RETURNS: + * Found address on success, 0 on failure. + */ +static phys_addr_t __init_memblock +__memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, + phys_addr_t size, phys_addr_t align, int nid) +{ + phys_addr_t this_start, this_end, cand; + u64 i; + + for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) { + this_start = clamp(this_start, start, end); + this_end = clamp(this_end, start, end); + + if (this_end < size) + continue; + + cand = round_down(this_end - size, align); + if (cand >= this_start) + return cand; + } + + return 0; +} + /** * memblock_find_in_range_node - find free area in given range and node * @start: start of candidate range @@ -92,15 +162,23 @@ static long __init_memblock memblock_overlaps_region(struct memblock_type *type, * * Find @size free area aligned to @align in the specified range and node. * + * When allocation direction is bottom-up, the @start should be greater + * than the end of the kernel image. Otherwise, it will be trimmed. The + * reason is that we want the bottom-up allocation just near the kernel + * image so it is highly likely that the allocated memory and the kernel + * will reside in the same node. + * + * If bottom-up allocation failed, will try to allocate memory top-down. + * * RETURNS: - * Found address on success, %0 on failure. + * Found address on success, 0 on failure. */ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, phys_addr_t end, phys_addr_t size, phys_addr_t align, int nid) { - phys_addr_t this_start, this_end, cand; - u64 i; + int ret; + phys_addr_t kernel_end; /* pump up @end */ if (end == MEMBLOCK_ALLOC_ACCESSIBLE) @@ -109,19 +187,39 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, /* avoid allocating the first page */ start = max_t(phys_addr_t, start, PAGE_SIZE); end = max(start, end); + kernel_end = __pa_symbol(_end); - for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) { - this_start = clamp(this_start, start, end); - this_end = clamp(this_end, start, end); + /* + * try bottom-up allocation only when bottom-up mode + * is set and @end is above the kernel image. + */ + if (memblock_bottom_up() && end > kernel_end) { + phys_addr_t bottom_up_start; - if (this_end < size) - continue; + /* make sure we will allocate above the kernel */ + bottom_up_start = max(start, kernel_end); - cand = round_down(this_end - size, align); - if (cand >= this_start) - return cand; + /* ok, try bottom-up allocation first */ + ret = __memblock_find_range_bottom_up(bottom_up_start, end, + size, align, nid); + if (ret) + return ret; + + /* + * we always limit bottom-up allocation above the kernel, + * but top-down allocation doesn't have the limit, so + * retrying top-down allocation may succeed when bottom-up + * allocation failed. + * + * bottom-up allocation is expected to be fail very rarely, + * so we use WARN_ONCE() here to see the stack trace if + * fail happens. + */ + WARN_ONCE(1, "memblock: bottom-up allocation failed, " + "memory hotunplug may be affected\n"); } - return 0; + + return __memblock_find_range_top_down(start, end, size, align, nid); } /** @@ -134,7 +232,7 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, * Find @size free area aligned to @align in the specified range. * * RETURNS: - * Found address on success, %0 on failure. + * Found address on success, 0 on failure. */ phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start, phys_addr_t end, phys_addr_t size, |
