Reset AG_pipeline bucket status after validation step. by vasunvidia · Pull Request #3155 · NVIDIA/Megatron-LM

vasunvidia · 2026-01-29T22:32:54Z

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        C1[Expert Review] --> C2[Final Review]
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copy-pr-bot · 2026-01-29T22:32:58Z

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shjwudp · 2026-02-04T01:39:01Z

megatron/core/pipeline_parallel/schedules.py

+                model_chunk.ddp_config.overlap_param_gather
+                and model_chunk.ddp_config.use_megatron_fsdp
+            ):
+                model_chunk.start_param_sync(sync_and_return=True)


Can start_param_sync(sync_and_return=True) be replaced with synchronize_param_gather here?

No I tried that. But it is not possible because it's not part of FullyShardedDataParallel class. We need to call synchronize_param_gather within start_param_sync

I see, could you try putting the synchronize_param_gather function on FullyShardedDataParallel(example)? The goal is to help keep the start_param_sync function simple, thank you.

dimapihtar · 2026-02-04T15:27:51Z

/ok to test 1be259b

Use synchronize_param_gather directly in forward_backward_func Cleanup

shjwudp

LGTM, thanks

gautham-kollu · 2026-04-07T16:10:48Z

/ok to test 5e06d9d

gautham-kollu · 2026-04-11T07:23:08Z

/ok to test 300df2f

gautham-kollu · 2026-04-13T15:44:39Z

/ok to test 67ab72e

gautham-kollu · 2026-04-13T17:07:02Z

megatron/core/pipeline_parallel/schedules.py

+    if forward_only:
+        for model_chunk in [model]:
+            if (
+                model_chunk.ddp_config.overlap_param_gather


Looks like tests are failing here
https://productionresultssa0.blob.core.windows.net/actions-results/37969e82-01e3-40a3-9888-0d4640918912/workflow-job-run-6e14b3cb-8310-59bb-b181-43ce9f423ada/logs/job/job-logs.txt?rsct=text%2Fplain&se=2026-04-13T17%3A15%3A32Z&sig=Y25Xx%2BzyRaqVuBFxJTGhliMWSFjdl%2FE5225d3OmfyiU%3D&ske=2026-04-13T18%3A48%3A04Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2026-04-13T14%3A48%3A04Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2026-04-13T17%3A05%3A27Z&sv=2025-11-05

2026-04-13T16:20:56.5057536Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5058127Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5058546Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5058976Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5059497Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5059875Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5060350Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5060797Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5061147Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5061594Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5062295Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5062718Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5063184Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5063560Z 2-task-1-0/0 [default0]:> 2026-04-13T16:20:56.5064019Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5064518Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5064924Z 2-task-1-0/0 [default0]:E 2026-04-13T16:20:56.5065430Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5066146Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5066792Z 2-task-1-0/0 [default0]: 2026-04-13T16:20:56.5067604Z 2-task-1-0/0 [default0]:WARNING 2026-04-13T16:20:56.5068516Z 2-task-1-0/0 [default0]:WARNING 2026-04-13T16:20:56.5069439Z 2-task-1-0/0 [default0]: def getattr(self, name: str) -> Union[Tensor, "Module"]:
if "parameters" in self.dict:
parameters = self.dict["parameters"]
if name in parameters:
return parameters[name]
if "buffers" in self.dict:
buffers = self.dict["buffers"]
if name in buffers:
return buffers[name]
if "modules" in self.dict:
modules = self.dict["modules"]
if name in modules:
return modules[name]
raise AttributeError(
f"'{type(self).name}' object has no attribute '{name}'"
)
AttributeError: 'GPTModel' object has no attribute 'ddp_config'

/usr/local/lib/python3.12/dist-packages/torch/nn/modules/module.py:1967: AttributeError
------------------------------ Captured log call -------------------------------
megatron.core.rerun_state_machine:rank_utils.py:43 Implicit initialization of Rerun State Machine!
megatron.core.rerun_state_machine:rank_utils.py:43 RerunStateMachine initialized in mode RerunMode.DISABLED
test_forward_vpp[tp_pp_vpp1-pp_layout1-False-True] ______________

check fsdp in enabled first

gautham-kollu · 2026-04-13T17:44:49Z

/ok to test 0db839b

None if not present

gautham-kollu · 2026-04-13T17:56:48Z

/ok to test 23c4fd1

gautham-kollu · 2026-04-13T17:58:30Z

/ok to test 3b68346

svcnvidia-nemo-ci · 2026-04-13T19:47:18Z

🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/24363433680

svcnvidia-nemo-ci · 2026-04-13T20:26:59Z

🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/24365170039

svcnvidia-nemo-ci · 2026-04-13T22:13:58Z

🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/24369618791

svcnvidia-nemo-ci · 2026-04-13T22:57:45Z

🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/24371185458

vasunvidia requested review from a team as code owners January 29, 2026 22:32

ko3n1g requested a review from a team January 29, 2026 22:33

erhoo82 added the complexity: low label Jan 29, 2026

erhoo82 added this to the Core 0.16 milestone Jan 29, 2026

erhoo82 added the Expert Review [deprecated] Apply this label to indicate that your PR is ready for expert review. label Jan 29, 2026

shjwudp reviewed Feb 4, 2026

View reviewed changes

dimapihtar requested review from erhoo82 and yanring February 4, 2026 15:27

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vasunvidia marked this pull request as draft March 17, 2026 17:29

vasunvidia force-pushed the vrengasamy/fsdp_cg_val_fix2 branch from 1be259b to b4bef4f Compare March 18, 2026 17:56

Reset AG_pipeline bucket status after validation step.

45016a4

Use synchronize_param_gather directly in forward_backward_func Cleanup

vasunvidia force-pushed the vrengasamy/fsdp_cg_val_fix2 branch from 5e36632 to 45016a4 Compare March 20, 2026 08:36

vasunvidia marked this pull request as ready for review March 30, 2026 17:47

shjwudp approved these changes Mar 31, 2026

View reviewed changes

Merge branch 'main' into vrengasamy/fsdp_cg_val_fix2

5e06d9d

yashaswikarnati approved these changes Apr 1, 2026

View reviewed changes

svcnvidia-nemo-ci added the Final Review PR is in the "final review" stage label Apr 1, 2026

Phlip79 removed the Expert Review [deprecated] Apply this label to indicate that your PR is ready for expert review. label Apr 1, 2026

ericharper approved these changes Apr 3, 2026

View reviewed changes

copy-pr-bot bot temporarily deployed to test April 10, 2026 21:39 Inactive

svcnvidia-nemo-ci added Approved All necessary approvals have been made and removed Final Review PR is in the "final review" stage labels Apr 10, 2026

Merge branch 'main' into vrengasamy/fsdp_cg_val_fix2

300df2f

copy-pr-bot bot temporarily deployed to test April 11, 2026 07:24 Inactive

Merge branch 'main' into vrengasamy/fsdp_cg_val_fix2

67ab72e

copy-pr-bot bot temporarily deployed to test April 13, 2026 15:45 Inactive

gautham-kollu reviewed Apr 13, 2026

View reviewed changes

gautham-kollu added 2 commits April 13, 2026 10:20

Update schedules.py

df28cf4

check fsdp in enabled first

Update schedules.py

0db839b

copy-pr-bot bot had a problem deploying to test April 13, 2026 17:45 Error

Update schedules.py

23c4fd1

None if not present

copy-pr-bot bot had a problem deploying to test April 13, 2026 17:57 Error

Update schedules.py

3b68346

copy-pr-bot bot temporarily deployed to test April 13, 2026 17:59 Inactive

gautham-kollu enabled auto-merge April 13, 2026 19:43

gautham-kollu added this pull request to the merge queue Apr 13, 2026

github-merge-queue bot removed this pull request from the merge queue due to failed status checks Apr 13, 2026

gautham-kollu added this pull request to the merge queue Apr 13, 2026

Merged via the queue into NVIDIA:main with commit 5f80f0a Apr 13, 2026
63 checks passed

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vasunvidia commented Jan 29, 2026

What does this PR do ?

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