From mboxrd@z Thu Jan 1 00:00:00 1970 From: mathieu.desnoyers@efficios.com (Mathieu Desnoyers) Date: Wed, 16 Feb 2011 15:39:53 -0500 Subject: [ltt-dev] Porting "jump labels" to userspace In-Reply-To: <4D5C30D8.8070107@caviumnetworks.com> References: <4D5AA164.1050607@polymtl.ca> <1297853778.3224.90.camel@springer.wildebeest.org> <20110216185056.CAD7B1806E0@magilla.sf.frob.com> <20110216200034.GA6066@Krystal> <20110216200449.1EB9618020E@magilla.sf.frob.com> <4D5C30D8.8070107@caviumnetworks.com> Message-ID: <20110216203953.GB2015@Krystal> * David Daney (ddaney at caviumnetworks.com) wrote: > 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. Indeed, the arch-specific parts will need some extra care (which might, in the worse case scenario, require to suspend a whole process during the update), but the generic code in jump_label.c and jump_label.h could certainly be reused. Thanks, Mathieu > > David Daney -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com