Huge thanks Alex, really good summary
Cheers
Mark.
> On 20 Jul 2015, at 18:17, Alex Bennée <alex.ben...@linaro.org> wrote:
>
> Hi,
>
> Following this afternoons call I thought I'd summarise the state of the
> various patch series and their relative dependencies. We re-stated the
> aim should be to get what is up-streamable through the review process
> and heading for merge so the delta for a full working MTTCG can be as
> low as possible. There was some concern about the practicality of
> submitting patches where the full benefit will not be seen until MTTCG
> is finally merged.
>
> On the patch submission note could I encourage posting public git trees
> along with the patches for ease of review?
>
> BQL lock breaking patches, Paolo/Jan
> - required for working virt-io in MTTCG
> - supersedes some of Fred's patches
> - merged upstream as of -rc0
>
> TCG async_safe_work, Fred
> - http://git.greensocs.com/fkonrad/mttcg.git async_work_v3
> - [1437144337-21442-1-git-send-email-fred.kon...@greensocs.com]
> - split from earlier MTTCG patch series
> - needed for cross-cpu sync mechanism for main series and slow-path
> - candidate for upstreaming, but only MTTCG uses for now?
>
> Slow-path for atomic instruction translation, Alvise
> - [1436516626-8322-1-git-send-email-a.r...@virtualopensystems.com]
> - Needs re-basing to use TCG async_safe_work
> - Earlier part of series (pre MTTCG) could be upstreamed as is
> - Concern about performance impact in non-MTTCG scenarios
> - Single CPU thread impact may be minimal with latest version, needs
> benchmarking
> - Also incomplete backend support, would BACKEND_HAS_LLSC_OPS be
> acceptable to maintainers while support added by more knowledgable
> backend people for non-x86/arm backends?
>
> Multi-threaded TCG V6, Fred
> - g...@git.greensocs.com:fkonrad/mttcg.git branch multi_tcg_v6
> - [1435330053-18733-1-git-send-email-fred.kon...@greensocs.com]
> - Needs re-basing on top of latest -rc (BQL breaking)
> - Contains the rest of the MTTCG work (tb locking, tlb stuff etc)
> - Currently target-arm only, other builds broken
>
> As far as balancing the desire to get things upstreamed versus having a
> stable base for testing I suggest we try an approach like this:
>
> - select the current upstream -rc as the common base point
> - create a branch from -rc with:
> - stuff submitted for upstream (reviewed, not nacked)
> - doesn't break any tree
> - has minimal performance impact
>
> Then both Fred and Alvise could base their trees of this point and we
> aim to rebase onto a new branch each time the patches get merged into a
> new upstream RC. The question then become how to deal with any
> cross-dependencies between the slow-path and the main MTTCG branches?
>
> I suspect the initial common branch point would just be
> 2.4.0-rc1+safe_async.
>
> Does that sound workable?
>
> --
> Alex Bennée
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+33 (0)603762104
mark.burton
