Re: [PATCH] task_struct colouring ...

H. Peter Anvin (hpa@zytor.com)
30 Nov 2001 17:05:20 -0800


Followup to: <Pine.LNX.4.40.0111301614000.1600-100000@blue1.dev.mcafeelabs.com>
By author: Davide Libenzi <davidel@xmailserver.org>
In newsgroup: linux.dev.kernel
>
> The point is why store kernel pointers in global registers when You can
> achieve the same functionality, with a smaller patch, that does not need
> to be recoded for each CPU, without using global registers.
>

Because global registers are faster! This is exactly the kind of
stuff that is properly CPU-dependent and should be treated as such.
Heck, it even depends on what kind of multiprocessor architecture, if
any, you're using!

That being said, I belive that on most, if not all, processors, the
idea of having the pointer point not to "current" but to a per-CPU
memory area is *very* appealing, and a change that should be made
uniform unless it's a significant lose on some machines...

-hpa

-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt	<amsp@zytor.com>
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