`_is_dsa_active` asked `getattr(server_args, "_is_dsa_model_arch", False)`, and
that name has never existed on `ServerArgs` -- it arrived as a placeholder with
the CP strategy abstractions (#27313), so the getattr default has always decided
the predicate. A dynamic read of a name nothing sets is the one shape the config
census cannot follow, and it looked like a live decision while being dead.
Spelled as the constant it evaluates to, with the placeholder written down: what
it should ask (whether this process runs a DSA model arch) is the CP path's
call, and its only consumer, `ContextParallelStrategy.per_layer_attn_cp_comm`,
has no readers yet.
That was the sole entry in the read ratchet's `_INERT_DYNAMIC_READS`, so the
exemption list is gone with it -- there is no way to exempt a read from the
baselines any more, which is the invariant worth having. The `counted()`
indirection it existed for goes too (verified the three shapes it guarded still
report: direct, `getattr`, and an attribute-parked alias).
Six reads were left on `self.server_args` outside the per-instance boundary the
plan reserves for the tokenizer-manager family, and each had a different reason
to be there:
- `scheduler.process_input_requests` (`mm_feature_transport`) and
`BaseSpecWorker._build_hicache_draft_plan` (`enable_hierarchical_cache`) are
plain leaves -> `get_mm()` / `get_memory()`.
- `DraftBackendFactory._create_backend` read the split backend through a
*runtime-computed name* (`getattr(self.server_args, backend_name)`) and then
fell back to the base field by hand -- the census's documented blind spot.
The two names it can be handed are exactly the pair `attention_backends()`
returns with that fallback already applied, so it reads the pair and indexes
it. The draft runner's own stamp still wins when it has one.
- `remote_instance_weight_loader_use_transfer_engine` and
`pre_capture_activation_reserve_mb` are derived members. Both are computed
from published leaves only, so both get a named accessor that derives from
the bags (and therefore follows a post-publish override).
The first of those two has all its inputs in one bag, so it follows the
established shape: one `*_of(cfg)` helper in `arg_groups/overrides.py`, the
`ServerArgs` member delegating to it, and the accessor calling it on
`get_model()`. `modelexpress_transport_of` splits out the JSON parse both
sides need. The second spans four bags plus the configured parallel sizes, so
it exists twice like the mamba pair -- and `TestDerivedPredicatesAgreeAcrossTiers`
now pins both new pairs equal over their input matrices (92 subtests).
`self.server_args.X` outside the tokenizer-manager family: 11 -> 5, and the
five that remain are the documented ones (the encode server's own record, the
nixl connector's rank arithmetic, `GrammarManager`'s handed instance).
The post-capture headroom path calls the same bag-backed
`pre_capture_activation_reserve_mb` accessor the configurator uses -- the
accessor advertises override-following, and a reserve that reads the record
while its sibling reads the bags can disagree after a post-publish override.
And the conversions' orphans go with them: `RemoteInstanceWeightTransporter`
kept a `server_args` field nothing reads, and `DraftBackendFactory` parked a
record it no longer consults -- both drop the parameter, and the four factory
call sites stop threading one.
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