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From: Andi Kleen <andi@firstfloor.org>
To: Matt Mackall <mpm@selenic.com>
Cc: Andi Kleen <andi@firstfloor.org>, Pavel Machek <pavel@suse.cz>,
	Ingo Molnar <mingo@elte.hu>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 1/2] Shrink compat_ioctl.c
Date: Tue, 30 Sep 2008 01:38:42 +0200	[thread overview]
Message-ID: <20080929233842.GW25711@one.firstfloor.org> (raw)
In-Reply-To: <1222730830.23159.12.camel@calx>

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

  parent reply	other threads:[~2008-09-29 23:33 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-29 23:27 [RFC PATCH 1/2] Shrink compat_ioctl.c Matt Mackall
2008-09-29 23:29 ` [RFC PATCH 2/2] " Matt Mackall
2008-09-29 23:38 ` Andi Kleen [this message]
2008-09-29 23:38   ` [RFC PATCH 1/2] " Matt Mackall

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