The arch-specific IOREMAP_MAX_ORDER is introduced in commit: ff0daca([ARM] Add section support to ioremap) and commit: a069c89 ([ARM] 3705/1: add supersection support to ioremap()). But supersections and sections mappings are only used in !SMP && !LPAE case. Otherwise, mapping is created using the usual 4K pages.
In most cases without !SMP && !LPAE, the big alignment cause high fragmentation issue in vmalloc area. Here we use arch-specific IOREMAP_MAX_ORDER only in !SMP && !LPAE case, otherwise use generic IOREMAP_MAX_ORDER in include/linux/vmalloc.h. Signed-off-by: Zhang Zhen <zhenzhang.zh...@huawei.com> --- arch/arm/include/asm/memory.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index b7f6fb4..3209012 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -76,10 +76,12 @@ */ #define XIP_VIRT_ADDR(physaddr) (MODULES_VADDR + ((physaddr) & 0x000fffff)) +#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) /* * Allow 16MB-aligned ioremap pages */ #define IOREMAP_MAX_ORDER 24 +#endif #else /* CONFIG_MMU */ -- 1.9.1 . -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/