Make core pinning explicit opt-in; disabled by default

crates/core/Cargo.toml

@@ -146,9 +146,8 @@ spacetimedb-wasm-instance-env-times = []
 test = ["spacetimedb-commitlog/test", "spacetimedb-datastore/test"]
 # Perfmaps for profiling modules
 perfmap = []
-# Disables core pinning
-no-core-pinning = []
-no-job-core-pinning = []
+# Enables core pinning.
+core-pinning = []
 
 [dev-dependencies]
 spacetimedb-lib = { path = "../lib", features = ["proptest", "test"] }

crates/core/src/startup.rs

@@ -319,10 +319,10 @@ impl Cores {
     /// Get the cores of the local host, as reported by the operating system.
     ///
     /// Returns `None` if `num_cpus` is less than 8
-    /// or if core pinning is disabled.
+    /// or if core pinning is not enabled.
     /// If `Some` is returned, the `Vec` is non-empty.
     pub fn get_core_ids() -> Option<Vec<CoreId>> {
-        if cfg!(feature = "no-core-pinning") {
+        if cfg!(not(feature = "core-pinning")) {
             return None;
         }
 

crates/core/src/util/jobs.rs

@@ -86,7 +86,7 @@ impl JobCores {
     /// and runs all databases in the `global_runtime`.
     pub fn from_pinned_cores(cores: impl IntoIterator<Item = CoreId>) -> Self {
         let cores: IndexMap<_, _> = cores.into_iter().map(|id| (id, CoreInfo::default())).collect();
-        let inner = if cfg!(feature = "no-job-core-pinning") || cores.is_empty() {
+        let inner = if cfg!(not(feature = "core-pinning")) || cores.is_empty() {
             JobCoresInner::NoPinning
         } else {
             JobCoresInner::PinnedCores(Arc::new(Mutex::new(PinnedCoresExecutorManager {

crates/standalone/Cargo.toml

@@ -21,9 +21,8 @@ unstable = ["spacetimedb-client-api/unstable"]
 allow_loopback_http_for_tests = ["spacetimedb-core/allow_loopback_http_for_tests"]
 # Perfmaps for profiling modules
 perfmap = ["spacetimedb-core/perfmap"]
-# Disables core pinning
-no-core-pinning = ["spacetimedb-core/no-core-pinning"]
-no-job-core-pinning = ["spacetimedb-core/no-job-core-pinning"]
+# Enables core pinning.
+core-pinning = ["spacetimedb-core/core-pinning"]
 
 [dependencies]
 spacetimedb-client-api-messages.workspace = true