Date: Wed, 23 Nov 2005 23:48:03 +0100
From: Pavel Machek <pavel@suse.cz>
To: Benjamin LaHaise <bcrl@kvack.org>
Cc: Andi Kleen <ak@suse.de>, linux-kernel@vger.kernel.org
Subject: Re: rfc/rft: use r10 as current on x86-64
Message-ID: <20051123224803.GE24220@elf.ucw.cz>
References: <20051122165204.GG1127@kvack.org>
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Hi!

> The patch below converts x86-64 to use r10 as the current pointer instead 
> of gs:pcurrent.  This results in a ~34KB savings in the code segment of 
> the kernel.  I've tested this with running a few regular applications, 
> plus a few 32 bit binaries.  If this patch is interesting, it probably 
> makes sense to merge the thread info structure into the task_struct so 
> that the assembly bits for syscall entry can be cleaned up.  Comments?

34KB smaller is nice, but is not it also 30% slower? Plus some inline
assembly *will* have %r10 hardcoded, no? I'd be afraid around crypto
code, for example.
								Pavel
-- 
Thanks, Sharp!
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