ye-luo added a comment. In D78075#2272474 <https://reviews.llvm.org/D78075#2272474>, @tianshilei1992 wrote:
> In D78075#2272398 <https://reviews.llvm.org/D78075#2272398>, @ye-luo wrote: > >>> However, OpenMP task has a problem that it must be within >>> to a parallel region; otherwise the task will be executed immediately. As a >>> result, if we directly wrap to a regular task, the nowait target outside of >>> a >>> parallel region is still a synchronous version. >> >> The spec says an implicit task can be generated by an implicit parallel >> region which can be the whole OpenMP program. For this reason, the need of >> explicit parallel region is a limitation of the llvm OpenMP runtime, right? >> >> Can I have an option to run the nowait region as a regular task instead of >> an unshackled task? So I can use "parallel" and well established ways to >> control the thread affinity. > > According to the spec, an implicit parallel region is an inactive parallel > region that is not generated from a parallel construct. And based on the > definition of active parallel region, which is a parallel region that is > executed by a team consisting of more than one thread, an inactive parallel > region only has one thread. Since we only have one thread, if we encounter a > task, executing it immediately does make sense as we don't have another > thread to execute it. If I remember correctly, you may yield the thread inside a target region after enqueuing kernels and transfers. So even with 1 thread, there is chance to run other tasks without finishing this target. Isn't that possible? > I do remember your request about the regular task. This patch is exactly what > you need. Later when I finish the RTL, I could provide an option. Thanks. I see, we will be able to control that in the runtime library. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D78075/new/ https://reviews.llvm.org/D78075 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
