Cleanup Elastic Scaling Checks for FeatureIndex::ElasticScalingMVP

polkadot/node/core/backing/src/lib.rs

@@ -106,7 +106,6 @@ use polkadot_node_subsystem_util::{
 };
 use polkadot_parachain_primitives::primitives::IsSystem;
 use polkadot_primitives::{
-	node_features::FeatureIndex,
 	vstaging::{
 		BackedCandidate, CandidateReceiptV2 as CandidateReceipt,
 		CommittedCandidateReceiptV2 as CommittedCandidateReceipt,
@@ -234,9 +233,7 @@ struct PerRelayParentState {
 	fallbacks: HashMap<CandidateHash, AttestingData>,
 	/// The minimum backing votes threshold.
 	minimum_backing_votes: u32,
-	/// If true, we're appending extra bits in the BackedCandidate validator indices bitfield,
-	/// which represent the assigned core index. True if ElasticScalingMVP is enabled.
-	inject_core_index: bool,
+	/// ElasticScalingMVP is enabled.
 	/// The number of cores.
 	n_cores: u32,
 	/// Claim queue state. If the runtime API is not available, it'll be populated with info from
@@ -610,7 +607,6 @@ fn table_attested_to_backed(
 		ValidatorSignature,
 	>,
 	table_context: &TableContext,
-	inject_core_index: bool,
 ) -> Option<BackedCandidate> {
 	let TableAttestedCandidate { candidate, validity_votes, group_id: core_index } = attested;
 
@@ -649,7 +645,7 @@ fn table_attested_to_backed(
 			.map(|(pos_in_votes, _pos_in_group)| validity_votes[pos_in_votes].clone())
 			.collect(),
 		validator_indices,
-		inject_core_index.then_some(core_index),
+		Some(core_index),
 	))
 }
 
@@ -1157,16 +1153,11 @@ async fn construct_per_relay_parent_state<Context>(
 		.await?
 		.unwrap_or(NodeFeatures::EMPTY);
 
-	let inject_core_index = node_features
-		.get(FeatureIndex::ElasticScalingMVP as usize)
-		.map(|b| *b)
-		.unwrap_or(false);
-
 	let executor_params =
 		per_session_cache.executor_params(session_index, parent, ctx.sender()).await;
 	let executor_params = try_runtime_api!(executor_params);
 
-	gum::debug!(target: LOG_TARGET, inject_core_index, ?parent, "New state");
+	gum::debug!(target: LOG_TARGET, ?parent, "New state");
 
 	let (validator_groups, group_rotation_info) = try_runtime_api!(groups);
 
@@ -1237,7 +1228,6 @@ async fn construct_per_relay_parent_state<Context>(
 		awaiting_validation: HashSet::new(),
 		fallbacks: HashMap::new(),
 		minimum_backing_votes,
-		inject_core_index,
 		n_cores: validator_groups.len() as u32,
 		claim_queue: ClaimQueueSnapshot::from(claim_queue),
 		validator_to_group,
@@ -1675,7 +1665,6 @@ async fn post_import_statement_actions<Context>(
 			if let Some(backed) = table_attested_to_backed(
 				attested,
 				&rp_state.table_context,
-				rp_state.inject_core_index,
 			) {
 				let para_id = backed.candidate().descriptor.para_id();
 				gum::debug!(
@@ -2157,7 +2146,6 @@ fn handle_get_backable_candidates_message(
 					table_attested_to_backed(
 						attested,
 						&rp_state.table_context,
-						rp_state.inject_core_index,
 					)
 				});
 

polkadot/node/core/provisioner/src/lib.rs

@@ -37,13 +37,12 @@ use polkadot_node_subsystem::{
 use polkadot_node_subsystem_util::{
 	has_required_runtime, request_availability_cores, request_persisted_validation_data,
 	request_session_index_for_child,
-	runtime::{prospective_parachains_mode, request_node_features, ProspectiveParachainsMode},
+	runtime::{prospective_parachains_mode, ProspectiveParachainsMode},
 	TimeoutExt,
 };
 use polkadot_primitives::{
-	node_features::FeatureIndex,
 	vstaging::{BackedCandidate, CandidateReceiptV2 as CandidateReceipt, CoreState},
-	BlockNumber, CandidateHash, CoreIndex, Hash, Id as ParaId, NodeFeatures,
+	BlockNumber, CandidateHash, CoreIndex, Hash, Id as ParaId,
 	OccupiedCoreAssumption, SessionIndex, SignedAvailabilityBitfield, ValidatorIndex,
 };
 use std::collections::{BTreeMap, HashMap};
@@ -83,15 +82,13 @@ impl ProvisionerSubsystem {
 /// Per-session info we need for the provisioner subsystem.
 pub struct PerSession {
 	prospective_parachains_mode: ProspectiveParachainsMode,
-	elastic_scaling_mvp: bool,
 }
 
 /// A per-relay-parent state for the provisioning subsystem.
 pub struct PerRelayParent {
 	leaf: ActivatedLeaf,
 	backed_candidates: Vec<CandidateReceipt>,
 	prospective_parachains_mode: ProspectiveParachainsMode,
-	elastic_scaling_mvp: bool,
 	signed_bitfields: Vec<SignedAvailabilityBitfield>,
 	is_inherent_ready: bool,
 	awaiting_inherent: Vec<oneshot::Sender<ProvisionerInherentData>>,
@@ -103,7 +100,6 @@ impl PerRelayParent {
 			leaf,
 			backed_candidates: Vec::new(),
 			prospective_parachains_mode: per_session.prospective_parachains_mode,
-			elastic_scaling_mvp: per_session.elastic_scaling_mvp,
 			signed_bitfields: Vec::new(),
 			is_inherent_ready: false,
 			awaiting_inherent: Vec::new(),
@@ -214,16 +210,10 @@ async fn handle_active_leaves_update(
 		if per_session.get(&session_index).is_none() {
 			let prospective_parachains_mode =
 				prospective_parachains_mode(sender, leaf.hash).await?;
-			let elastic_scaling_mvp = request_node_features(leaf.hash, session_index, sender)
-				.await?
-				.unwrap_or(NodeFeatures::EMPTY)
-				.get(FeatureIndex::ElasticScalingMVP as usize)
-				.map(|b| *b)
-				.unwrap_or(false);
 
 			per_session.insert(
 				session_index,
-				PerSession { prospective_parachains_mode, elastic_scaling_mvp },
+				PerSession { prospective_parachains_mode },
 			);
 		}
 
@@ -289,7 +279,6 @@ async fn send_inherent_data_bg<Context>(
 	let signed_bitfields = per_relay_parent.signed_bitfields.clone();
 	let backed_candidates = per_relay_parent.backed_candidates.clone();
 	let mode = per_relay_parent.prospective_parachains_mode;
-	let elastic_scaling_mvp = per_relay_parent.elastic_scaling_mvp;
 
 	let mut sender = ctx.sender().clone();
 
@@ -307,7 +296,6 @@ async fn send_inherent_data_bg<Context>(
 			&signed_bitfields,
 			&backed_candidates,
 			mode,
-			elastic_scaling_mvp,
 			return_senders,
 			&mut sender,
 			&metrics,
@@ -414,7 +402,6 @@ async fn send_inherent_data(
 	bitfields: &[SignedAvailabilityBitfield],
 	candidates: &[CandidateReceipt],
 	prospective_parachains_mode: ProspectiveParachainsMode,
-	elastic_scaling_mvp: bool,
 	return_senders: Vec<oneshot::Sender<ProvisionerInherentData>>,
 	from_job: &mut impl overseer::ProvisionerSenderTrait,
 	metrics: &Metrics,
@@ -466,7 +453,6 @@ async fn send_inherent_data(
 		&bitfields,
 		candidates,
 		prospective_parachains_mode,
-		elastic_scaling_mvp,
 		leaf.hash,
 		from_job,
 	)
@@ -679,7 +665,6 @@ async fn select_candidate_hashes_from_tracked(
 /// Should be called when prospective parachains are enabled.
 async fn request_backable_candidates(
 	availability_cores: &[CoreState],
-	elastic_scaling_mvp: bool,
 	bitfields: &[SignedAvailabilityBitfield],
 	relay_parent: Hash,
 	sender: &mut impl overseer::ProvisionerSenderTrait,
@@ -741,11 +726,6 @@ async fn request_backable_candidates(
 	for (para_id, core_count) in scheduled_cores_per_para {
 		let para_ancestors = ancestors.remove(&para_id).unwrap_or_default();
 
-		// If elastic scaling MVP is disabled, only allow one candidate per parachain.
-		if !elastic_scaling_mvp && core_count > 1 {
-			continue
-		}
-
 		let response = get_backable_candidates(
 			relay_parent,
 			para_id,
@@ -778,7 +758,6 @@ async fn select_candidates(
 	bitfields: &[SignedAvailabilityBitfield],
 	candidates: &[CandidateReceipt],
 	prospective_parachains_mode: ProspectiveParachainsMode,
-	elastic_scaling_mvp: bool,
 	relay_parent: Hash,
 	sender: &mut impl overseer::ProvisionerSenderTrait,
 ) -> Result<Vec<BackedCandidate>, Error> {
@@ -792,7 +771,6 @@ async fn select_candidates(
 		ProspectiveParachainsMode::Enabled { .. } =>
 			request_backable_candidates(
 				availability_cores,
-				elastic_scaling_mvp,
 				bitfields,
 				relay_parent,
 				sender,

prdoc/pr_7286.prdoc

@@ -0,0 +1,20 @@
+title: Remove feature flag checks for Elastic Scaling MVP
+doc:
+- audience: Runtime Dev
+  description: |
+    ## Description
+    This PR addresses [issue #6352](https://github.com/paritytech/polkadot-sdk/issues/6352), which proposes cleaning up the codebase by assuming that the FeatureIndex::ElasticScalingMVP feature is always enabled.
+
+    ## Integration
+    - Removed the traces of the `elastic_scaling_mvp`  scaling limitation   (provisioner)
+    - Removed the traces of `inject_core_index` scaling limitation   (backing)
+
+    ## Review Notes
+    - The inject_core_index flag is used to support elastic scaling. When true, the core index is injected into the BackedCandidate, enabling dynamic core allocation and deallocation.
+    - I removed this check in the backing file since we assume elastic scaling is enabled.
+
+crates:
+- name: polkadot-node-core-backing
+  bump: patch
+- name: polkadot-node-core-provisioner
+  bump: patch