Messages in this thread | | | Date | Tue, 26 Feb 2019 06:28:45 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [RFC PATCH] tools/memory-model: Remove (dep ; rfi) from ppo |
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On Tue, Feb 26, 2019 at 02:49:06PM +0100, Peter Zijlstra wrote: > On Tue, Feb 26, 2019 at 12:38:13PM +0100, Borislav Petkov wrote: > > On Tue, Feb 26, 2019 at 12:30:08PM +0100, Peter Zijlstra wrote: > > > When I used the argc variant, gcc-8 'works', but with s/argc/1/ it is > > > still broken. > > > > As requested on IRC: > > What I asked was if you could get your GCC developer friends to have a > look at this :-)
Yes, this all is a bit on the insane side from a kernel viewpoint. But the paper you found does not impose this; it has instead been there for about 20 years, back before C and C++ admitted to the existence of concurrency. But of course compilers are getting more aggressive, and yes, some of the problems show up in single-threaded code.
The usual response is "then cast the pointers to intptr_t!" but of course that breaks type checking.
There is an effort to claw back the concurrency pieces, and I would be happy to run the resulting paper past you guys.
I must confess to not being all that sympathetic to code that takes advantage of happenstance stack-frame layout. Is there some reason we need that?
Thanx, Paul
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