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Date: Fri, 13 Apr 2001 21:40:16 -0700 (PDT)
From: Linus Torvalds <torvalds@transmeta.com>
To: Rik van Riel <riel@conectiva.com.br>
cc: "Adam J. Richter" <adam@yggdrasil.com>, <linux-kernel@vger.kernel.org>
Subject: Re: PATCH(?): linux-2.4.4-pre2: fork should run child first
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On Sat, 14 Apr 2001, Rik van Riel wrote:
>
> Also, have you managed to find a real difference with this?

It actually makes a noticeable difference on lmbench, so I think adam is
100% right.

> If it turns out to be beneficial to run the child first (you
> can measure this), why not leave everything the same as it is
> now but have do_fork() "switch threads" internally ?

Probably doesn't much matter. We've invalidated the TLB anyway due to the
page table copy, so the cost of switching the MM is not all that
noticeable.

		Linus

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