Lightning

Changed

- Changed the behavior of `on_epoch_start` to run at the beginning of validation & test epoch (6498)

Removed

- Removed legacy code to include `step` dictionary returns in `callback_metrics`. Use `self.log_dict` instead. (6682)

Fixed

- Fixed `DummyLogger.log_hyperparams` raising a `TypeError` when running with `fast_dev_run=True` (6398)
- Fixed error on TPUs when there was no `ModelCheckpoint` (6654)
- Fixed `trainer.test` freeze on TPUs (6654)
- Fixed a bug where gradients were disabled after calling `Trainer.predict` (6657)
- Fixed bug where no TPUs were detected in a TPU pod env (6719)


Contributors

awaelchli, carmocca, ethanwharris, kaushikb11, rohitgr7, tchaton

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Changed

- Added Autocast in validation, test and predict modes for Native AMP (6565)
- Update Gradient Clipping for the TPU Accelerator (6576)
- Refactored setup for typing friendly (6590)

Fixed

- Fixed a bug where `all_gather` would not work correctly with `tpu_cores=8` (6587)
- Fixed comparing required versions (6434)
- Fixed duplicate logs appearing in console when using the python logging module (6275)


Contributors

awaelchli, Borda, ethanwharris, justusschock, kaushikb11

_If we forgot someone due to not matching commit email with GitHub account, let us know :]_

Changed

- Changed the default of `find_unused_parameters` back to `True` in DDP and DDP Spawn (6438)

Fixed

- Expose DeepSpeed loss parameters to allow users to fix loss instability (6115)
- Fixed DP reduction with collection (6324)
- Fixed an issue where the tuner would not tune the learning rate if also tuning the batch size (4688)
- Fixed broadcast to use PyTorch `broadcast_object_list` and add `reduce_decision` (6410)
- Fixed logger creating directory structure too early in DDP (6380)
- Fixed DeepSpeed additional memory use on rank 0 when default device not set early enough (6460)
- Fixed `DummyLogger.log_hyperparams` raising a `TypeError` when running with `fast_dev_run=True` (6398)
- Fixed an issue with `Tuner.scale_batch_size` not finding the batch size attribute in the datamodule (5968)
- Fixed an exception in the layer summary when the model contains torch.jit scripted submodules (6511)
- Fixed when Train loop config was run during `Trainer.predict` (6541)

Contributors
awaelchli, kaushikb11, Palzer, SeanNaren, tchaton

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Fixed

- Fixed `ModelPruning(make_pruning_permanent=True)` pruning buffers getting removed when saved during training (6073)
- Fixed when `_stable_1d_sort` to work when `n >= N` (6177)
- Fixed `AttributeError` when `logger=None` on TPU (6221)
- Fixed PyTorch Profiler with `emit_nvtx` (6260)
- Fixed `trainer.test` from `best_path` hangs after calling `trainer.fit` (6272)
- Fixed `SingleTPU` calling `all_gather` (6296)
- Ensure we check deepspeed/sharded in multinode DDP (6297)
- Check `LightningOptimizer` doesn't delete optimizer hooks (6305)
- Resolve memory leak for evaluation (6326)
- Ensure that clip gradients is only called if the value is greater than 0 (6330)
- Fixed `Trainer` not resetting `lightning_optimizers` when calling `Trainer.fit()` multiple times (6372)

Contributors
awaelchli, carmocca, Chizuchizu, frankier, SeanNaren, tchaton

_If we forgot someone due to not matching commit email with GitHub account, let us know :]_

Added

- Added `checkpoint` parameter to callback's `on_save_checkpoint` hook (6072)

Changed

- Changed the order of `backward`, `step`, `zero_grad` to `zero_grad`, `backward`, `step` (6147)
- Changed default for DeepSpeed CPU Offload to False, due to prohibitively slow speeds at smaller scale (6262)

Fixed

- Fixed epoch level schedulers not being called when `val_check_interval < 1.0` (6075)
- Fixed multiple early stopping callbacks (6197)
- Fixed incorrect usage of `detach()`, `cpu()`, `to()` (6216)
- Fixed LBFGS optimizer support which didn't converge in automatic optimization (6147)
- Prevent `WandbLogger` from dropping values (5931)
- Fixed error thrown when using valid distributed mode in multi node (6297)


Contributors
akihironitta, borisdayma, carmocca, dvolgyes, SeanNaren, SkafteNicki

_If we forgot someone due to not matching commit email with GitHub account, let us know :]_

Fixed

- Fixed incorrect yield logic for the amp autocast context manager (6080)
- Fixed priority of plugin/accelerator when setting distributed mode (6089)
- Fixed error message for AMP + CPU incompatibility (6107)

Contributors
awaelchli, SeanNaren, carmocca

_If we forgot someone due to not matching commit email with GitHub account, let us know :]_