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  • 00:45
    vksnk synchronize #4467
  • 00:45

    vksnk on pos_inf-memory-assert

    Use has_upper_bound() to check … (compare)

  • 00:43
    vksnk closed #4459
  • 00:43
    vksnk commented #4459
  • 00:36
    vksnk opened #4467
  • 00:32

    vksnk on pos_inf-memory-assert

    Check if shared memory allocati… (compare)

  • 00:31

    abadams on master

    Increase max device count to qu… Merge pull request #4464 from h… (compare)

  • 00:31
    abadams closed #4464
  • 00:31
    abadams commented #4464
  • 00:17
    abadams synchronize #4439
  • 00:17

    abadams on define_div_by_zero

    x % 0 == x Fix the definitions… (compare)

  • Dec 10 23:58
    abadams commented #4461
  • Dec 10 23:57
    abadams commented #4461
  • Dec 10 23:49
    dsharletg commented #4461
  • Dec 10 23:49
    dsharletg commented #4461
  • Dec 10 23:38
    dsharletg commented #4465
  • Dec 10 23:36
    dsharletg synchronize #4461
  • Dec 10 23:36

    dsharletg on fix-fft

    Add alternative codepath for sm… (compare)

  • Dec 10 23:27
    abadams commented #4439
  • Dec 10 21:40
    steven-johnson closed #4431
Zalman Stern
@zvookin
I'm not sure it makes much sense to consider until we are looking at a different way of lowering async
I.e. in the current model, synchronous copy is probably required anyway. The thread doing it would just wait immediately if it wasn't synchronous.
"Event model" likely amounts to exposing the semaphore abstraction and arranging for it to be signaled by the device support code somehow
Andrew Adams
@abadams
Overlapping CPU computation with device stuff works fine. All use of the device_api occurs on a single thread. All the CPU compute occurs on another thread.
That's what I'm targeting for now
Zalman Stern
@zvookin
"CPU" is not necessarily correct there. It can be a different device too.
That is the common case for Hexagon right?
Andrew Adams
@abadams
For the hexagon DMA work so far, "CPU" is hexagon, and "device" is the dma engine
Zalman Stern
@zvookin
Ok, but the Hexagon may be invoked via offload.
Andrew Adams
@abadams
But yeah, I think it would work to have cross-device stuff going on in parallel
All use of each device interface would be on a single distinct thread
Zalman Stern
@zvookin
yes
Andrew Adams
@abadams
and there's no cross-device-interface serialization I think
so it would just work
Zalman Stern
@zvookin
That is what I was highlighting.
The only issue I see with this design is that the overhead of the thread may be too high to use for very lightweight hardware synchronization mechanisms. Other than that, I don't see a lot of reason to do the customized lowering.
I need to make a couple more changes to the hexagon DMA
Will try to do so today.
The test only calls buffer_copy, which is mostly as it should be.
Dillon Sharlet
@dsharletg
So BTW regarding hexagon offloading, I've been thinking we simply punt on that for now
and only target standalone
anything that we get working on standalone can be made to work with offloading without solving any "hard" problems like async + storage folding, it just might involve a lot of plumbing and infrastructure
Steven Johnson
@steven-johnson
re: the windows buildbots, proposed fix is out there.
Zalman Stern
@zvookin
I'll have to consider the implications, but I think the current stuff just works if the DMA things are scheduled inside an offloaded thing.
Dillon Sharlet
@dsharletg
I think there might be some hiccups with the device interface
that will need to get plumbed over via offloading
and I don't think that will happen transparently right now
it might be easy to make it work though
Zalman Stern
@zvookin
yeah, that's small boogs territory.
I guess I'm expecting it will have to work with offload very early on to have a useful test.
Andrew Adams
@abadams
@dsharletg the host->device case also works, but there's no benefit for cuda because the version without async already manages to overlap the cpu compute and copies in a subtle way.
Confused me for a while.
CPU compute -> synchronous copy -> async kernel launch -> next batch of CPU compute (overlapped with GPU kernel launch) -> synchronous copy (stalls until kernel launch is done) ->
Wait, so I guess the CPU compute is hidden under the GPU compute
not the copy
Dillon Sharlet
@dsharletg
That's great news!
Steven Johnson
@steven-johnson
I’m restarting the buildbot master now
Steven Johnson
@steven-johnson
On the recent issue of exported symbols varying between opt levels: it looks like CMake added a feature in 3.4 that attempts to auto-build a .def file for you on Windows, with the net effect of (mostly) acting like the gcc-ish default of “export all symbols”: https://blog.kitware.com/create-dlls-on-windows-without-declspec-using-new-cmake-export-all-feature/
I haven’t tried it (and we are talking about CMake here so who knows)...
Steven Johnson
@steven-johnson
We explicitly forbid using ‘.’ in a Func name since we use that as a separator internally, but we don’t seem to have a similar constraint on Var name. Deliberate or accidental?
Andrew Adams
@abadams
Var names are not uniqued either
Accidental I think
Zalman Stern
@zvookin
Var names are not uniqued by design
They're value types
Steven Johnson
@steven-johnson
Right
Andrew Adams
@abadams
Lack of '.' enforcement is the accidental thing
Steven Johnson
@steven-johnson
Just idly wondering if more constraints on the names allowed would give us more flexibility in the future. (e.g. GeneratorParam names are limited to C-style identifier rules, with additional constraints on underscore usage). Probably overthinking it.
Re: the windows buildbots: I updated the scripts and did a buildbot stop and start, but builds completing since then still seem to be using the old, broken windows testing approach. I wonder, do the workers queue up the commands on the worker (and thus this could be just stale builds completing)? Investigating...
Steven Johnson
@steven-johnson
Hmm, this is odd: I stopped buildbot again; when restarting, it is now failing with "could not find buildbot-www; is it installed?” which is something I haven’t seen before. @abadams, is it wise/unwise to restart the entire buildbot VM when updating?
Steven Johnson
@steven-johnson
logout, log back in, now starting it is telling me I need a txrequests package installed. Oy.