Add cost-model bench (#2168)

* Add cost-model bench

* cost_model bench with feature activated

cost-model/benches/cost_model.rs

@@ -0,0 +1,77 @@
+#![feature(test)]
+extern crate test;
+use {
+    solana_cost_model::cost_model::CostModel,
+    solana_sdk::{
+        feature_set::FeatureSet,
+        hash::Hash,
+        message::Message,
+        pubkey::Pubkey,
+        signature::Keypair,
+        signer::Signer,
+        system_instruction,
+        transaction::{SanitizedTransaction, Transaction},
+    },
+    test::Bencher,
+};
+
+struct BenchSetup {
+    transactions: Vec<SanitizedTransaction>,
+    feature_set: FeatureSet,
+}
+
+const NUM_TRANSACTIONS_PER_ITER: usize = 1024;
+
+fn setup(num_transactions: usize) -> BenchSetup {
+    let transactions = (0..num_transactions)
+        .map(|_| {
+            // As many transfer instructions as is possible in a regular packet.
+            let from_keypair = Keypair::new();
+            let to_lamports =
+                Vec::from_iter(std::iter::repeat_with(|| (Pubkey::new_unique(), 1)).take(24));
+            let ixs = system_instruction::transfer_many(&from_keypair.pubkey(), &to_lamports);
+            let message = Message::new(&ixs, Some(&from_keypair.pubkey()));
+            let transaction = Transaction::new(&[from_keypair], message, Hash::default());
+            SanitizedTransaction::from_transaction_for_tests(transaction)
+        })
+        .collect();
+
+    let feature_set = FeatureSet::default();
+
+    BenchSetup {
+        transactions,
+        feature_set,
+    }
+}
+
+#[bench]
+fn bench_cost_model(bencher: &mut Bencher) {
+    let BenchSetup {
+        transactions,
+        feature_set,
+    } = setup(NUM_TRANSACTIONS_PER_ITER);
+
+    bencher.iter(|| {
+        for transaction in &transactions {
+            let _ = CostModel::calculate_cost(test::black_box(transaction), &feature_set);
+        }
+    });
+}
+
+#[bench]
+fn bench_cost_model_requested_write_locks(bencher: &mut Bencher) {
+    let BenchSetup {
+        transactions,
+        mut feature_set,
+    } = setup(NUM_TRANSACTIONS_PER_ITER);
+    feature_set.activate(
+        &solana_sdk::feature_set::cost_model_requested_write_lock_cost::id(),
+        0,
+    );
+
+    bencher.iter(|| {
+        for transaction in &transactions {
+            let _ = CostModel::calculate_cost(test::black_box(transaction), &feature_set);
+        }
+    });
+}