Messages in this thread | | | Date | Wed, 20 Jun 2007 17:59:27 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [patch 1/9] Conditional Calls - Architecture Independent Code |
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* Adrian Bunk (bunk@stusta.de) wrote: > On Thu, Jun 14, 2007 at 12:02:42PM -0400, Mathieu Desnoyers wrote: > >... > > Well, we must take into account where these markers are added and how > > often the marked code is run. Since I mark very highly used code paths > > (interrupt handlers, page faults, lockdep code) and also plan to mark > > other code paths like the VM subsystem, adding cycles to these code > > paths seems like a no-go solution for standard distribution kernels. > >... > > People can get really picky when they have to decide wether or not they > > compile-in a profiling or tracing infrastructure in a distribution > > kernel. If the impact is detectable when they are not doing any tracing > > nor profiling, their reflex will be to compile it out so they can have > > the "maximum performance". This is why I am going through the trouble of > > making the markers impact as small as possible. > > Now that we finally hear what this code is required for, can we discuss > on this basis whether this is wanted and required? > > Including the question which abuse possibilities such an infrastructure > offers, and whether this is wanted in distribution kernels. >
Hi Adrian,
The purpose of this infrastructure has never been a secret; it is a piece taken from the Linux Kernel Markers. I proposed the first implementation of markers in December 2006.
Please use the following link as a starting point to the thorough discussion that has already been held on this matter.
First, a huge discussion thread back in November 2006, where the need for a marker infrastructure has been recognized: http://lwn.net/Articles/200059/
A good summary of my recent previous post on kerneltrap: http://kerneltrap.org/node/8186
If you have new specific concerns to bring forward, I will be glad to discuss them with you.
Regards,
Mathieu
-- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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