Re: [RFC PATCH 1/2] Shrink compat_ioctl.c

Andi Kleen
2008-09-29T23:33:23Z

On Mon, Sep 29, 2008 at 06:27:10PM -0500, Matt Mackall wrote:
> I'm throwing this out untested as I don't have a mixed 64/32 system
> handy at the moment.

Makes sense (assuming it works, haven't tested)

> compat_ioctl: shrink structures
>
> Initially, compat_ioctl.c has a ~18k table of translated ioctls.
> Each table entry is 24 bytes but we can shrink this to 16:
>
> - use short table indexes rather than a pointer for .next values
> - use unsigned ints for cmd numbers (they're 32-bit ioctls, after all)
>
> In addition, there's a 2k hash table that we can do away with simply
> by hashifying the main table in place at init time.

You mean by using a closed hash?

Acked-by: Andi Kleen <ak@linux.intel.com>

-Andi