Home » Mailing list archives » linux-kernel » 2008 » April » 28

Re: [patch 0/2] Immediate Values - jump patching update

!MAILaRCHIVE_VOTE_RePLACE
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
[view in full thread]
From: Ingo Molnar <mingo@...>
To: H. Peter Anvin <hpa@...>
Cc: Mathieu Desnoyers <mathieu.desnoyers@...>, <akpm@...>, <linux-kernel@...>
Subject: Re: [patch 0/2] Immediate Values - jump patching update
Date: Monday, April 28, 2008 - 4:25 pm

* H. Peter Anvin <hpa@zytor.com> wrote:


hm, can it result in a broken kernel? If yes, how? Or are your 
objections more higher level?

i actually like that we end up with something rather NOP-ish, with some 
mild 'ambient' impact due to the extra constraints that state value 
visibility brings with it. The in-source impact of the markers is 
minimal, especially with Peter Zijstra's wrappers. The scheduler markers 
at least are also expected to stay pretty stable as well.

the syscall markers should be done less intrusively - and i think they 
can be done less intrusively.

but we need to get past this current impasse, the optimizations that 
Mathieu has done to markers are pretty impressive so far. The overhead 
is not zero, but it gets quite close to it and the SystemTap and kprobes 
people are happy with it as well.


it would clearly fall under the Fair Use Doctrine and perhaps also under 
the Doctrine of Severe Necessities, so dont be shy!

	Ingo
--
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
Messages in current thread:
[patch 0/2] Immediate Values - jump patching update, Mathieu Desnoyers, (Sun Apr 27, 11:34 pm)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Mon Apr 28, 1:21 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Ingo Molnar, (Mon Apr 28, 4:25 pm)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Mon Apr 28, 5:03 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Ingo Molnar, (Mon Apr 28, 6:11 pm)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Mon Apr 28, 6:25 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Ingo Molnar, (Mon Apr 28, 6:44 pm)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Mon Apr 28, 7:06 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Mathieu Desnoyers, (Mon Apr 28, 9:46 pm)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Mon Apr 28, 10:07 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Mathieu Desnoyers, (Tue Apr 29, 8:18 am)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Tue Apr 29, 11:35 am)
Re: [patch 0/2] Immediate Values - jump patching update, Mathieu Desnoyers, (Sun May 4, 10:54 am)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Sun May 4, 5:05 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Frank Ch. Eigler, (Mon Apr 28, 8:47 pm)
Re: [patch 0/2] Immediate Values - jump patching update, H. Peter Anvin, (Mon Apr 28, 9:08 pm)
Re: [patch 0/2] Immediate Values - jump patching update, Ingo Molnar, (Tue Apr 29, 8:08 am)
Re: [patch 0/2] Immediate Values - jump patching update, Pavel Machek, (Wed May 14, 10:53 am)
Re: [patch 0/2] Immediate Values - jump patching update, Ingo Molnar, (Mon Apr 28, 8:48 am)
Re: [patch 0/2] Immediate Values - jump patching update, Mathieu Desnoyers, (Mon Apr 28, 10:35 am)