Fix flaky test_self_e2e_pd_perturb (#27426)

2026-06-06 19:31:08 +08:00
parent 9a48bf75f5
commit 99cf0a4399
2 changed files with 19 additions and 2 deletions
@@ -37,7 +37,14 @@ class _PDPerturbBase(CanaryPDFixture):
    ) -> None:
        # send_parallel_short_requests defaults to max_new_tokens=100 so D-side runs
        # decode forwards that exercise canary verify on the transferred prefix.
-        self.send_parallel_short_requests(n=4)
+        #
+        # distinct_prompts is required for the violation to surface reliably:
+        # with a shared prompt, P-side radix caching rewrites each request's
+        # req_to_token row to the first-inserted (canonical) copy's slots in
+        # cache_unfinished_req BEFORE send_kv_chunk snapshots the indices, so a
+        # flip on a deduped duplicate slot is freed untransferred and never
+        # re-verified on either side.
+        self.send_parallel_short_requests(n=4, distinct_prompts=True)
        # D-side: first decode forward re-verifies the transferred prefix slots,
        # so the flip MUST surface as real_kv_hash violation.
        self.assert_per_forward_violation_reported(