On Tue, Apr 29, 2014 at 05:59:27AM +0100, Jungseok Lee wrote: > --- a/Documentation/arm64/memory.txt > +++ b/Documentation/arm64/memory.txt > @@ -8,10 +8,11 @@ This document describes the virtual memory layout used by > the AArch64 > Linux kernel. The architecture allows up to 4 levels of translation > tables with a 4KB page size and up to 3 levels with a 64KB page size. > > -AArch64 Linux uses 3 levels of translation tables with the 4KB page > -configuration, allowing 39-bit (512GB) virtual addresses for both user > -and kernel. With 64KB pages, only 2 levels of translation tables are > -used but the memory layout is the same. > +AArch64 Linux uses 3 levels and 4 levels of translation tables with > +the 4KB page configuration, allowing 39-bit (512GB) and 48-bit (256TB) > +virtual addresses, respectively, for both user and kernel. With 64KB > +pages, only 2 levels of translation tables are used but the memory layout > +is the same.
Any reason why we couldn't use 48-bit address space with 64K pages (implying 3 levels)? > -AArch64 Linux memory layout with 64KB pages: > +AArch64 Linux memory layout with 4KB pages + 4 levels: > + > +Start End Size Use > +----------------------------------------------------------------------- > +0000000000000000 0000ffffffffffff 256TB user > + > +ffff000000000000 ffff7bfffffeffff ~124TB vmalloc BTW, maybe as a separate patch we should change the "end" to be exclusive. It becomes harder to modify (I've been through this a few times already ;)) and even follow the changes. -- Catalin -- 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/
