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Subject: Re: Accelerating user mode linux
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Richard Zidlicky <rz@linux-m68k.org>
Cc: Jeff Dike <jdike@karaya.com>, Alan Cox <alan@redhat.com>,
       linux-kernel@vger.kernel.org
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On Fri, 2002-08-02 at 12:34, Richard Zidlicky wrote:
> I have once ported Basilisk to work native on linux-m68k. It works
> *slow* so I looked what the problem is - the signal delivery in
> Linux is exorbitantly slow. Eg an SIGILL delivery costs ~ 1650 cycles 
> on a 68060, compared to that sigreturn and getpid are 200-250 and 
> sched_yield with context switch around 400.

The numbers look very different on a real processor. Signal delivery is
indeed not stunningly fast but relative to a context switch its very low
indeed.

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