From owner-freebsd-smp  Thu Sep 12  5:21:37 2002
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Date: Thu, 12 Sep 2002 05:20:28 -0700
From: Terry Lambert <tlambert2@mindspring.com>
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To: Luigi Rizzo <rizzo@icir.org>
Cc: Bruce Evans <bde@zeta.org.au>, smp@FreeBSD.ORG
Subject: Re: wakeup handling on SMP boxes
References: <20020911172143.H93521@iguana.icir.org> <20020912204245.I5891-100000@gamplex.bde.org> <20020912043148.B98062@iguana.icir.org>
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Luigi Rizzo wrote:
> > > now, this is another debatable thing -- why do processes sleep at
> > > high priority at all given that they are not holding any locks while
> > > sleeping ?
> >
> > So that they get run soon after they wake up.  The priority doesn't matter
> > while they are asleep, but the system needs to know what priority to use
> > when it wakes them.
> 
> ok but why they need to run soon ? again, they are not holding any
> resource, so they could as well keep their priority and be
> scheduled according to it (which is something that will happen
> anyways when they do an usrret).

Because iterative operations are bound by latency.

Consider your own work in the network stack to increase
throughput.

-- Terry

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