The official source reports this update: v1.15.0: FSDP2 activation memory, dtensor improvements. v1.15.0: FSDP2 activation memory, dtensor improvements FSDP2 A large batch of FSDP2 work this release: two fixes that cut activation memory at long sequence lengths, tied-embedding support on torch >= 2.13, and a round of checkpointing correctness and scale fixes. Activation checkpointing was wrapping each child of the matched layer ( self_attn , mlp , the norms) instead of the layer itself, so every inter-child activation stayed saved for backward. It now wraps the layer.
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FSDP2 activation memory reduced for long sequences in v1.15.0
FSDP2 activation checkpointing now wraps the entire transformer layer, reducing saved activations.
9 Sept 20261 verified claims1 sources1 observations
This official update documents a development concerning v1.15.0: FSDP2 activation memory, dtensor improvements. Its practical significance depends on the scope and evidence stated by the source.
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