From 5576d4547f46588b7a67e9ef7b363c14e0789250 Mon Sep 17 00:00:00 2001
From: Alexey Shekhirin <5773434+shekhirin@users.noreply.github.com>
Date: Mon, 15 Dec 2025 14:05:54 +0000
Subject: [PATCH] revert: feat(engine): run sync state root if not enough
 parallelism (#20127) (#20378)

---
 crates/engine/primitives/src/config.rs           | 9 ++-------
 crates/engine/tree/src/tree/payload_validator.rs | 2 +-
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/crates/engine/primitives/src/config.rs b/crates/engine/primitives/src/config.rs
index bd96c45ae2..10265b9a43 100644
--- a/crates/engine/primitives/src/config.rs
+++ b/crates/engine/primitives/src/config.rs
@@ -101,7 +101,7 @@ pub struct TreeConfig {
     state_provider_metrics: bool,
     /// Cross-block cache size in bytes.
     cross_block_cache_size: u64,
-    /// Whether the host has enough parallelism to run state root in parallel.
+    /// Whether the host has enough parallelism to run state root task.
     has_enough_parallelism: bool,
     /// Whether multiproof task should chunk proof targets.
     multiproof_chunking_enabled: bool,
@@ -403,17 +403,12 @@ impl TreeConfig {
         self
     }
 
-    /// Setter for whether or not the host has enough parallelism to run state root in parallel.
+    /// Setter for has enough parallelism.
     pub const fn with_has_enough_parallelism(mut self, has_enough_parallelism: bool) -> Self {
         self.has_enough_parallelism = has_enough_parallelism;
         self
     }
 
-    /// Whether or not the host has enough parallelism to run state root in parallel.
-    pub const fn has_enough_parallelism(&self) -> bool {
-        self.has_enough_parallelism
-    }
-
     /// Setter for state provider metrics.
     pub const fn with_state_provider_metrics(mut self, state_provider_metrics: bool) -> Self {
         self.state_provider_metrics = state_provider_metrics;
diff --git a/crates/engine/tree/src/tree/payload_validator.rs b/crates/engine/tree/src/tree/payload_validator.rs
index 1ba2a1d1b8..3fc003c8be 100644
--- a/crates/engine/tree/src/tree/payload_validator.rs
+++ b/crates/engine/tree/src/tree/payload_validator.rs
@@ -876,7 +876,7 @@ where
     /// Note: Use state root task only if prefix sets are empty, otherwise proof generation is
     /// too expensive because it requires walking all paths in every proof.
     const fn plan_state_root_computation(&self) -> StateRootStrategy {
-        if self.config.state_root_fallback() || !self.config.has_enough_parallelism() {
+        if self.config.state_root_fallback() {
             StateRootStrategy::Synchronous
         } else if self.config.use_state_root_task() {
             StateRootStrategy::StateRootTask