More standard staking miner deposits (#3621)

polkadot/runtime/kusama/src/lib.rs

@@ -345,11 +345,8 @@ parameter_types! {
 
 	// signed config
 	pub const SignedMaxSubmissions: u32 = 16;
-	pub const SignedDepositBase: Balance = deposit(1, 0);
-	// A typical solution occupies within an order of magnitude of 50kb.
-	// This formula is currently adjusted such that a typical solution will spend an amount equal
-	// to the base deposit for every 50 kb.
-	pub const SignedDepositByte: Balance = deposit(1, 0) / (50 * 1024);
+	pub const SignedDepositBase: Balance = deposit(2, 0);
+	pub const SignedDepositByte: Balance = deposit(0, 10) / 1024;
 	// Each good submission will get 1/10 KSM as reward
 	pub SignedRewardBase: Balance =  UNITS / 10;
 	// fallback: emergency phase.
@@ -1921,3 +1918,17 @@ sp_api::impl_runtime_apis! {
 		}
 	}
 }
+
+#[cfg(test)]
+mod tests_fess {
+	use super::*;
+	use sp_runtime::assert_eq_error_rate;
+
+	#[test]
+	fn signed_deposit_is_sensible() {
+		// ensure this number does not change, or that it is checked after each change.
+		// a 1 MB solution should need around 0.16 KSM deposit
+		let deposit = SignedDepositBase::get() + (SignedDepositByte::get() * 1024 * 1024);
+		assert_eq_error_rate!(deposit, UNITS * 16 / 100, UNITS / 100);
+	}
+}