pallet_broker: Let start_sales calculate and request the correct core count (#4221)

substrate/frame/broker/src/lib.rs

@@ -559,27 +559,22 @@ pub mod pallet {
 		///
 		/// - `origin`: Must be Root or pass `AdminOrigin`.
 		/// - `initial_price`: The price of Bulk Coretime in the first sale.
-		/// - `total_core_count`: This is the total number of cores the relay chain should have
-		/// after the sale concludes.
+		/// - `extra_cores`: Number of extra cores that should be requested on top of the cores
+		///   required for `Reservations` and `Leases`.
 		///
-		/// NOTE: This function does not actually request that new core count from the relay chain.
-		/// You need to make sure to call `request_core_count` afterwards to bring the relay chain
-		/// in sync.
-		///
-		/// When to call the function depends on the new core count. If it is larger than what it
-		/// was before, you can call it immediately or even before `start_sales` as non allocated
-		/// cores will just be `Idle`. If you are actually reducing the number of cores, you should
-		/// call `request_core_count`, right before the next sale, to avoid shutting down tasks too
-		/// early.
+		/// This will call [`Self::request_core_count`] internally to set the correct core count on
+		/// the relay chain.
 		#[pallet::call_index(4)]
-		#[pallet::weight(T::WeightInfo::start_sales((*total_core_count).into()))]
+		#[pallet::weight(T::WeightInfo::start_sales(
+			T::MaxLeasedCores::get() + T::MaxReservedCores::get() + *extra_cores as u32
+		))]
 		pub fn start_sales(
 			origin: OriginFor<T>,
 			initial_price: BalanceOf<T>,
-			total_core_count: CoreIndex,
+			extra_cores: CoreIndex,
 		) -> DispatchResultWithPostInfo {
 			T::AdminOrigin::ensure_origin_or_root(origin)?;
-			Self::do_start_sales(initial_price, total_core_count)?;
+			Self::do_start_sales(initial_price, extra_cores)?;
 			Ok(Pays::No.into())
 		}