Messages in this thread | | | Date | Sat, 20 Mar 2010 05:46:52 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH RFC 00/11] lock monitor: Separate features related to lock |
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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.
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