linux-mips
[Top] [All Lists]

Re: [RFC] FPU context switch

To: Jun Sun <jsun@mvista.com>
Subject: Re: [RFC] FPU context switch
From: Dominic Sweetman <dom@algor.co.uk>
Date: Tue, 17 Sep 2002 22:44:12 +0100
Cc: linux-mips@linux-mips.org
In-reply-to: <20020917110423.E17321@mvista.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20020917110423.E17321@mvista.com>
Sender: linux-mips-bounce@linux-mips.org
Jun Sun (jsun@mvista.com) writes:

> 1) always blindly save and restore during context switch (switch_to())

Just a suggestion...

> Not interesting.  Just list it here for completeness.

Agreed, it's not interesting.

But it would work, every time; while the current scheme has been a
fertile source of interesting bugs.  How much useful optimisation
might have been done with the effort required to fix them?

Saving all the FPU registers on a 400MHz CPU takes about a tenth of a
microsecond.  Does anyone reading this list have evidence that this is
ever any kind of problem?

Dominic Sweetman
MIPS Technologies.


<Prev in Thread] Current Thread [Next in Thread>