Project

General

Profile

Task #2679

Task #2675: bonded CUDA offload task

bonded GPU offload task assignment

Added by Szilárd Páll over 2 years ago. Updated over 2 years ago.

Status:
Closed
Priority:
Normal
Assignee:
Category:
mdrun
Target version:
Difficulty:
uncategorized
Close

Description

To be implemented:
- -bonded auto/cpu/gpu command line option
- new task and valid assignments to the PP or PP+PME ranks' GPU
- only offload if all available listed interaction types are supported at first
- default behavior (TBD based on performance)

Associated revisions

Revision a07e8b21 (diff)
Added by Mark Abraham over 2 years ago

Task assignment for bonded interactions on CUDA GPUs

Made a query function to find whether any interactions of supported
times exist in the global topology, so that we can make efficient
high-level decisions.

Added free for gpuBondedLists pointer.

Minor cleanup in manage-threading.h

Fixes #2679

Change-Id: I0ebbbd33c2cba5808561111b0ec6160bfd2f840d

History

#1 Updated by Szilárd Páll over 2 years ago

Note that in my latest tests bonded offload with rnase on a Quadro P6000 (simiar to a 1080Ti) it takes more work to offload the bonded interactions than to execute all listed kernels + reduction on half of a slow CPU (and about the same amount of time if we just add up kernel times).

Hence, for small inputs we need to fuse kernels and/or disable bonded offload, I think.

#2 Updated by Mark Abraham over 2 years ago

Szilárd Páll wrote:

To be implemented:
- -bonded auto/cpu/gpu command line option

Done

- new task and valid assignments to the PP or PP+PME ranks' GPU

Done

- only offload if all available listed interaction types are supported at first

Berk's changes mean we don't need this

- default behavior (TBD based on performance)

Currently always on if supported and NB is on GPU.

#3 Updated by Gerrit Code Review Bot over 2 years ago

Gerrit received a related patchset '1' for Issue #2679.
Uploader: Mark Abraham ()
Change-Id: gromacs~master~I0ebbbd33c2cba5808561111b0ec6160bfd2f840d
Gerrit URL: https://gerrit.gromacs.org/8535

#4 Updated by Szilárd Páll over 2 years ago

  • Status changed from New to In Progress
  • Assignee set to Mark Abraham

Currently always on if supported and NB is on GPU.

OK. I suggest we keep it that way and tweak defaults post-beta as we'll need more benchmarks to know when is is worth offloading.

#5 Updated by Mark Abraham over 2 years ago

  • Status changed from In Progress to Resolved

#6 Updated by Mark Abraham over 2 years ago

  • Status changed from Resolved to Closed

Also available in: Atom PDF