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[baseline5] fix ctx_len=2147450879

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2026-08-20 12:23:50 +00:00
parent 56d0c18605
commit 12d2ad55bd
1 changed files with 12 additions and 12 deletions
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24
qwen3_6_scripts/paged_attn.py
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@@ -1878,21 +1878,21 @@ class PagedAttention:
# Guard against uninitialized context_lens entries (0x7FFF7FFF
# pattern) from chunked prefill + GDN capture boundary metadata
# race — same issue that forward_decode guards against for
# seq_lens. Clamp to max possible value (seq_len) and log once.
_max_ctx = int(context_lens.max().item()) if context_lens.numel() > 0 else 0
_max_sl = int(seq_lens_tensor.max().item()) if seq_lens_tensor.numel() > 0 else 0
if _max_ctx > _max_sl:
import logging as _logging
_logging.getLogger(__name__).warning(
"[BI100 PAGED_ATTN] context_lens contains value %d "
"> max seq_len %d, clamping (likely uninitialized "
"metadata from chunked prefill + GDN boundary race)",
_max_ctx, _max_sl)
context_lens = context_lens.clamp(max=0)
# race. Per-entry clamp inside the loop below, using block_tables
# physical capacity as absolute ceiling.
_max_physical_ctx = block_tables.shape[1] * block_size if block_tables.numel() > 0 else 0
for i in range(batch_size):
ctx_len = int(context_lens[i].item())
# Per-entry guard: if ctx_len exceeds physical KV capacity,
# it's an uninitialized 0x7FFF7FFF sentinel — force to 0.
if ctx_len < 0 or ctx_len > _max_physical_ctx:
import logging as _logging
_logging.getLogger(__name__).warning(
"[BI100 PAGED_ATTN] context_lens[%d]=%d exceeds "
"physical capacity %d, forcing to 0",
i, ctx_len, _max_physical_ctx)
ctx_len = 0
q_start = int(query_start_loc[i].item())
q_end = int(query_start_loc[i + 1].item())
q_len = q_end - q_start