similar to: parallel-lib: New LLVM Suproject

Thanks for your help, Tanya! I haven't created the project in SVN yet. Am I able to set it up myself on the LLVM servers, or does someone else need to do that part? I'll be glad to volunteer to moderate the new mailing lists. We will want a website. I think there will be a top-level docs directory for the project and a docs directory for each subproject. To begin with, StreamExecutor

I talked to Chandler about the name "offload_libs" vs "parallel_libs" and he said he thinks "offload" is too narrow of a term for the scope he sees for this subproject. One example he brought up was AVX 512. He thinks that code explicitly targeting CPU parallelism should also be included in this project, even though it doesn't fit in the category of

I've put together a proposed "charter" for this new project, which I am calling parallel_utils (although I'm very open to suggestions for a better name). The text of my charter is below, and I welcome any input on how it can be improved. ===================================================== LLVM Parallel Utils Subproject Charter

The parallel-libs LLVM subproject is now set up and ready for code development. This is the subproject that is meant to house the StreamExecutor parallel runtime library, possibly the OpenMP target runtime libraries, and other libraries devoted to handling parallelism in LLVM (see the README currently checked into the parallel-libs base directory for the project charter). The parallel-libs

> On Apr 22, 2016, at 3:01 PM, Chandler Carruth <chandlerc at gmail.com> wrote: > > I feel like this thread got a bit stalled. I'd like to pick it up and try to suggest a path forward. > > I don't hear any real objections to the overall idea of having an LLVM subproject for parallelism runtimes and support libraries. I think we should get that created. I think it

Chandler, It seems that the general consensus is to save further discussions for later and go ahead with your proposal. I can add my +1 to this as well. Could you / Jason prepare a proposal on the new project, with all the usual questions covered? One interesting thing is where to put SE and libomptarget in the project's tree. I would be happy to review it from Intel / OpenMP side. Also, as

I respect Hal's more tactful approach and response.. Let me play devils advocate for a minute 1) Yet another programming model - Is the advantage spelled out somewhere? (I know there are reasons, but I'd like to see a FAQ or this clearly documented. Examples pretty please.. More for long term than my own selfish benefit) 2) Is this an "open standard" - If I wanted to propose a

Ahh, I just noticed that Chandler's proposal is to put SE only into this new project, and to keep libomptarget separately, in OpenMP project. I wonder why so? Why SE (a library serving only one PPM so far) is different from libomptarget (a library also serving only one PPM so far)? Are people have opinion on this? Yours, Andrey ===== Software Engineer Intel Compiler Team On Tue, Apr 26,

Alexandre, Thanks for further shedding some light on the way OpenMP handles dependencies between tasks. I'm sorry for leaving that out of my document, it was just because I didn't know much about the way OpenMP handled its workflows. On Mon, Mar 28, 2016 at 11:43 AM Jason Henline <jhen at google.com> wrote: > Hi Carlo, > > Thanks for helping to clarify this point about

Hi Carlo, Thanks for helping to clarify this point about libomptarget vs liboffload, I have been getting confused about it myself. I think the open question concerns libomptarget not liboffload (others can correct me if I have misunderstood). My analysis from looking through the code was that libomptarget had some similarities with the platform support in SE, so I just wanted to consider how

Hi Sergos, Am I got it right, that SE interfaces are bound to the stream that is passed as argument? As I can see the stream is an abstraction of the target - hence data transfers for particular stream is limited to this stream? As for libomptarget implementation the data once offloaded can be reused in all offload entries, without additional data transfer. Is it possible in SE approach? If I

Jason, Am I got it right, that SE interfaces are bound to the stream that is passed as argument? As I can see the stream is an abstraction of the target - hence data transfers for particular stream is limited to this stream? As for libomptarget implementation the data once offloaded can be reused in all offload entries, without additional data transfer. Is it possible in SE approach? Regarding

Hi Jason, The long discussion made me wondering where this was going, but re-reading you original email [0], there was an acknowledgment of a potential future merge between the projects, and I can of make sense of the current picture. So you can forget about my question below! [0]: http://lists.llvm.org/pipermail/llvm-dev/2016-March/096576.html

Jason, > If I understand your interpretation of streams, it does not match my > understanding. SE follows the CUDA meaning of "stream". I think of a stream > as a "work queue" and each device can have several active streams. Memory > space on the device does not belong to any stream, so any stream can access > it. The thing that does belong to the stream is the

Hi Jason, This is probably because I'm not aware of the details, but it was claimed in this thread that liboffload can target Xeon Phi and Nvidia GPUs. Adding a new library that the compiler has to be aware of has to bring significant benefit. So it is not clear to me yet why the compiler should target two different runtime libraries that seems to have large chunk of overlapping

Hola Chandler, On Tue, Mar 15, 2016 at 1:44 PM, Chandler Carruth via Openmp-dev < openmp-dev at lists.llvm.org> wrote: > It seems like if the OpenMP folks want to add a liboffload plugin to > StreamExecutor, that would be an awesome additional platform, but I don't > see why we need to force the coupling here. > > Let me give you a reason: while user-facing sides of

I think it would be great if StreamExecutor could use liboffload to perform its offloading under the hood. Right now offloading is handled in StreamExecutor using platform plugins, so I think it could be very natural for us to write a plugin which basically forwards to liboffload. If that worked out, we could delete our current plugins and depend only on those based on liboffload, and then all the

Would it be parallel-libs/libomptarget/ or parallel-libs/omp/libomptarget/ To me the second way seems better because it seems likely that other OpenMP stuff could end up in there in the long run. Once we decide on which code to share, I think we will end up with new directories at the top level for those common components. On Thu, Jun 16, 2016 at 10:59 AM C Bergström <cbergstrom at

I did a more thorough read through liboffload and wrote up a more detailed doc describing how StreamExecutor platforms relate to libomptarget RTL interfaces. The doc also describes why the lack of support for streams in libomptarget makes it impossible to implement some of the most important StreamExecutor platforms in terms of libomptarget (

Thanks for your input, Hal. I think that having support for running host-side tasks makes this library much more useful, not only for acceleratorless systems, but even for those with accelerators (especially if you can place dependency edges between the host tasks and the accelerator tasks). Based on your comments, I think that supporting host-side tasks sounds like something that should be