Messages in this thread | | | Date | Tue, 11 Sep 2018 13:32:50 +0100 | From | Quentin Perret <> | Subject | Re: [PATCH v6 03/14] PM: Introduce an Energy Model management framework |
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Hi Andrea,
On Tuesday 11 Sep 2018 at 11:34:56 (+0200), Andrea Parri wrote: > FYI, the directory "tools/memory-model/" provides an "automated > memory-barriers.txt": in short, you encode your "memory ordering > questions" into "litmus tests" to be passed to the tool/simulator; > the tool will then answer with "Yes/No" (plus other information). > > Some preparation is required to set up and learn how to use the > LKMM tools, but once there, I expect them to be more "efficient" > than reading memory-barriers.txt... ;-)
Thanks for pointing this out, I'll have a look.
> Please don't hesitate > to contact me/the LKMM maintainers if you need help with this.
And thanks for that too.
> You'd need some info in order to write down a _well-formed litmus > test, e.g., matching barrier/synchronization and interested memory > accesses on the reader side (IAC, the replacement "store-release > -> store-once+smp_wmb" discussed above is suspicious...).
Regarding the disccusion above, I was actually planning on removing the smp_wmb entirely and rely on WRITE_ONCE + mutex_{un}lock here. Do you see something obviously wrong with that ?
I guess the LKMM tools should give me the yes/no answer I want, but if that's a no, I'd also like to understand why ... :-)
Thanks, Quentin
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