### What this PR does / why we need it?
fix the position 3 acceptance rate for eagle3 and pcp enabled
detail:
In the merged graph of eagle_proposer, the code logic was changed from
updating the code once before the forward pass of the draft model to
updating all three positions of common_attn_metadata in the merged graph
before performing the forward pass of the model. As a result, the update
of position 2 and position 3 affected the update of position 1.
For example, in the following field:
common_attn_metadata.block_table_tensor[:batch_size] =
common_attn_metadata.block_table_tensor[block_indices]
When updating the block_table_tensor at position 2, the modification of
this field occurred at the original address of common_attn_metadata. As
a result, the parameter at position 1 was also modified, but the forward
pass at position 1 had not been performed. Therefore, a copy of the
address of block_table_tensor needs to be made, and the modification
needs to be performed on the new address to ensure complete isolation
between positions.
### Does this PR introduce _any_ user-facing change?
no
### How was this patch tested?
tests and ut
- vLLM version: v0.18.0
- vLLM main:
8b6325758c
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Signed-off-by: lilinsiman <lilinsiman@gmail.com>
95d33f05c2