Re: [PATCH RFC 00/11] lock monitor: Separate features related to lock

[Frederic Weisbecker <fweisbec@gmail.com>]

On Fri, Mar 19, 2010 at 08:56:00AM -0400, Mathieu Desnoyers wrote:
> > Sure. My doubt is: currently with the upstream version, does the
> > compiler tend to load the parameters to the stack before the branch is
> > checked? Or is this a magic that jmp labels bring for whatever reason?
> 
> Even without the static jump patching, the compiler takes care of putting the
> stack setup after the branch is checked. That worked with a standard test on a
> variable, with immediate values and should still work with asm gotos.


Ok.


 
> I already did some presentations around these question. You can refer to my OLS
> 2008 slides, where I proposed static jump patching (ancestor of the asm gotos,
> where I did the liveness analysis myself in the back of the compiler; good
> enough for a prototype ;) ). Slide 11 discusses the branch vs stack setup
> question:
> 
> http://lttng.org/files/slides/desnoyers-talk-ols2008.pdf
> 
> Even more in Sections 8.1, 8.2 and 8.3 of my thesis:
> 
> http://lttng.org/files/thesis/desnoyers-dissertation-2009-12-v27.pdf
> 
> 8.1 Kernel Markers
> 8.2 Tracepoints
> 8.3 Immediate Values


Cool. I was already keeping your thesis on hand anyway :)

Thanks.