From mboxrd@z Thu Jan  1 00:00:00 1970
From: ddaney@caviumnetworks.com (David Daney)
Date: Wed, 16 Feb 2011 12:17:28 -0800
Subject: [ltt-dev] Porting "jump labels" to userspace
In-Reply-To: <20110216200449.1EB9618020E@magilla.sf.frob.com>
References: <4D5AA164.1050607@polymtl.ca>	<y0mvd0ltgba.fsf@fche.csb>	<AANLkTi=Nsy6fXE9=Njxs9LPHuohHzf=q5kD+fK765Rht@mail.gmail.com>	<1297853778.3224.90.camel@springer.wildebeest.org>	<20110216185056.CAD7B1806E0@magilla.sf.frob.com>	<20110216200034.GA6066@Krystal>
	<20110216200449.1EB9618020E@magilla.sf.frob.com>
Message-ID: <4D5C30D8.8070107@caviumnetworks.com>

On 02/16/2011 12:04 PM, Roland McGrath wrote:
> IMHO there is not really so much to the in-kernel implementation that it's
> worth attempting to reuse the code in userland.  Pretty much all the work
> is in the details of the implementation that would naturally differ a lot
> in a different context.  If you understand the mechanism and the machine
> details, then implementing it well for a userland context is not a big deal
> and is cleaner to do from scratch than shoe-horning kernel-centric code
> into a wildly different context.
>

Good point.

Certainly the details of maintaining instruction cache coherency may be 
different in userspace.

David Daney