Re: [PATCH] Documentation: riscv: tableize memory layout

From: Conor Dooley
Date: Sun Nov 06 2022 - 06:23:08 EST


On Sun, Nov 06, 2022 at 05:02:40PM +0700, Bagas Sanjaya wrote:
> Documentation: riscv: tableize memory layout

Minor nit about the $subject - but this is the docs, so I guess there's
nowhere better to mention grammar: "tableize" is not a word. I think
what you want here is "tabulate".

> The memory layout is written as table but it is inside literal code
^ as a table ^ inside a

Anyway, those are minor nits I saw in passing, one actual comment and a
simple question below.
Thanks,
Conor.

> block, which renders as preformatted text. Write the layout in reST
> grid table instead.
>
> Signed-off-by: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
> ---
> Documentation/riscv/vm-layout.rst | 120 +++++++++++++++---------------
> 1 file changed, 58 insertions(+), 62 deletions(-)
>
> diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst
> index 5b36e45fef60bd..139320e35de81f 100644
> --- a/Documentation/riscv/vm-layout.rst
> +++ b/Documentation/riscv/vm-layout.rst
> @@ -30,70 +30,66 @@ the RISC-V Linux Kernel resides.
> RISC-V Linux Kernel SV39
> ------------------------
>
> -::
> -
> - ========================================================================================================================
> - Start addr | Offset | End addr | Size | VM area description
> - ========================================================================================================================
> - | | | |
> - 0000000000000000 | 0 | 0000003fffffffff | 256 GB | user-space virtual memory, different per mm
> - __________________|____________|__________________|_________|___________________________________________________________
> - | | | |
> - 0000004000000000 | +256 GB | ffffffbfffffffff | ~16M TB | ... huge, almost 64 bits wide hole of non-canonical
> - | | | | virtual memory addresses up to the -256 GB
> - | | | | starting offset of kernel mappings.
> - __________________|____________|__________________|_________|___________________________________________________________
> - |
> - | Kernel-space virtual memory, shared between all processes:
> - ____________________________________________________________|___________________________________________________________
> - | | | |
> - ffffffc6fee00000 | -228 GB | ffffffc6feffffff | 2 MB | fixmap
> - ffffffc6ff000000 | -228 GB | ffffffc6ffffffff | 16 MB | PCI io
> - ffffffc700000000 | -228 GB | ffffffc7ffffffff | 4 GB | vmemmap
> - ffffffc800000000 | -224 GB | ffffffd7ffffffff | 64 GB | vmalloc/ioremap space
> - ffffffd800000000 | -160 GB | fffffff6ffffffff | 124 GB | direct mapping of all physical memory
> - fffffff700000000 | -36 GB | fffffffeffffffff | 32 GB | kasan
> - __________________|____________|__________________|_________|____________________________________________________________
> - |
> - |
> - ____________________________________________________________|____________________________________________________________
> - | | | |
> - ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF
> - ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel
> - __________________|____________|__________________|_________|____________________________________________________________
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | Start addr | Offset | End addr | Size | VM area description |
> + +==================+=========+==================+=========+==========================================================+
> + | 0000000000000000 | 0 | 0000003fffffffff | 256 GB | user-space virtual memory, different per mm |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | 0000004000000000 | +256 GB | ffffffbfffffffff | ~16M TB | ... huge, almost 64 bits wide hole of non-canonical |
> + | | | | | virtual memory addresses up to the -256 GB |
> + | | | | | starting offset of kernel mappings. |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | Kernel-space virtual memory, shared between all processes: |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | ffffffc6fee00000 | -228 GB | ffffffc6feffffff | 2 MB | fixmap |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | ffffffc6ff000000 | -228 GB | ffffffc6ffffffff | 16 MB | PCI io |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
^
Will these numbers remain right-aligned in the formatted doc? They were
aligned before in the text form & no longer appear to be.

> + | ffffffc700000000 | -228 GB | ffffffc7ffffffff | 4 GB | vmemmap |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | ffffffc800000000 | -224 GB | ffffffd7ffffffff | 64 GB | vmalloc/ioremap space |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | ffffffd800000000 | -160 GB | fffffff6ffffffff | 124 GB | direct mapping of all physical memory |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | fffffff700000000 | -36 GB | fffffffeffffffff | 32 GB | kasan |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | Identical layout to the 39-bit one from here on: |

This one /is/ sv39. I'd leave this as a blank to match the styling in
the original document.

> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
> + | ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel |
> + +------------------+---------+------------------+---------+----------------------------------------------------------+
>
>