Currently cma areas without a fixed base address are allocated close to the end of the node. This placement is sub-optimal because of how the compaction works: it effectively moves pages into the cma area. In particular, it often brings in hot executable pages, even if there is a plenty of free memory on the machine. This results in more cma allocation failures.
Instead let's place cma areas close to the beginning of a node. Cma first tries to start with highmem_start, so we shouldn't mess up with DMA32. In this case the compaction will help to free cma areas, resulting in better cma allocation success rates. Signed-off-by: Roman Gushchin <[email protected]> --- include/linux/memblock.h | 5 +++-- mm/cma.c | 4 ++-- mm/memblock.c | 26 +++++++++++++++----------- 3 files changed, 20 insertions(+), 15 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 9c5cc95c7cee..698188066450 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -384,8 +384,9 @@ static inline int memblock_get_region_node(const struct memblock_region *r) phys_addr_t memblock_phys_alloc_range(phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end); phys_addr_t memblock_alloc_range_nid(phys_addr_t size, - phys_addr_t align, phys_addr_t start, - phys_addr_t end, int nid, bool exact_nid); + phys_addr_t align, phys_addr_t start, + phys_addr_t end, int nid, bool exact_nid, + bool bottom_up); phys_addr_t memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid); static inline phys_addr_t memblock_phys_alloc(phys_addr_t size, diff --git a/mm/cma.c b/mm/cma.c index 20c4f6f40037..1b42be6d059b 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -332,13 +332,13 @@ int __init cma_declare_contiguous_nid(phys_addr_t base, */ if (base < highmem_start && limit > highmem_start) { addr = memblock_alloc_range_nid(size, alignment, - highmem_start, limit, nid, true); + highmem_start, limit, nid, true, true); limit = highmem_start; } if (!addr) { addr = memblock_alloc_range_nid(size, alignment, base, - limit, nid, true); + limit, nid, true, true); if (!addr) { ret = -ENOMEM; goto err; diff --git a/mm/memblock.c b/mm/memblock.c index b8b7be0561c4..c334b401fe16 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -272,6 +272,7 @@ __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, * %MEMBLOCK_ALLOC_ACCESSIBLE * @nid: nid of the free area to find, %NUMA_NO_NODE for any node * @flags: pick from blocks based on memory attributes + * @bottom_up: force bottom-up allocation * * Find @size free area aligned to @align in the specified range and node. * @@ -289,7 +290,8 @@ __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end, static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end, int nid, - enum memblock_flags flags) + enum memblock_flags flags, + bool bottom_up) { phys_addr_t kernel_end, ret; @@ -305,9 +307,10 @@ static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, /* * try bottom-up allocation only when bottom-up mode - * is set and @end is above the kernel image. + * is set and @end is above the kernel image or + * the bottom-up mode is enforced. */ - if (memblock_bottom_up() && end > kernel_end) { + if ((memblock_bottom_up() && end > kernel_end) || bottom_up) { phys_addr_t bottom_up_start; /* make sure we will allocate above the kernel */ @@ -359,7 +362,7 @@ phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start, again: ret = memblock_find_in_range_node(size, align, start, end, - NUMA_NO_NODE, flags); + NUMA_NO_NODE, flags, false); if (!ret && (flags & MEMBLOCK_MIRROR)) { pr_warn("Could not allocate %pap bytes of mirrored memory\n", @@ -1331,6 +1334,7 @@ __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone, * @end: the upper bound of the memory region to allocate (phys address) * @nid: nid of the free area to find, %NUMA_NO_NODE for any node * @exact_nid: control the allocation fall back to other nodes + * @bottom_up: force bottom-up allocation * * The allocation is performed from memory region limited by * memblock.current_limit if @end == %MEMBLOCK_ALLOC_ACCESSIBLE. @@ -1351,7 +1355,7 @@ __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone, phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size, phys_addr_t align, phys_addr_t start, phys_addr_t end, int nid, - bool exact_nid) + bool exact_nid, bool bottom_up) { enum memblock_flags flags = choose_memblock_flags(); phys_addr_t found; @@ -1367,14 +1371,14 @@ phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size, again: found = memblock_find_in_range_node(size, align, start, end, nid, - flags); + flags, bottom_up); if (found && !memblock_reserve(found, size)) goto done; if (nid != NUMA_NO_NODE && !exact_nid) { found = memblock_find_in_range_node(size, align, start, end, NUMA_NO_NODE, - flags); + flags, bottom_up); if (found && !memblock_reserve(found, size)) goto done; } @@ -1423,7 +1427,7 @@ phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size, __func__, (u64)size, (u64)align, &start, &end, (void *)_RET_IP_); return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE, - false); + false, false); } /** @@ -1442,7 +1446,7 @@ phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size, phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid) { return memblock_alloc_range_nid(size, align, 0, - MEMBLOCK_ALLOC_ACCESSIBLE, nid, false); + MEMBLOCK_ALLOC_ACCESSIBLE, nid, false, false); } /** @@ -1484,12 +1488,12 @@ static void * __init memblock_alloc_internal( max_addr = memblock.current_limit; alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid, - exact_nid); + exact_nid, false); /* retry allocation without lower limit */ if (!alloc && min_addr) alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid, - exact_nid); + exact_nid, false); if (!alloc) return NULL; -- 2.26.2
