Io Gas adjustments

1. read bytes charged in 4k steps
2. remove per write op free quota

aptos-move/aptos-gas-schedule/src/gas_schedule/transaction.rs

@@ -79,12 +79,19 @@ crate::gas_schedule::macros::define_gas_parameters!(
         [
             storage_io_per_state_slot_read: InternalGasPerArg,
             { 0..=9 => "load_data.base", 10.. => "storage_io_per_state_slot_read"},
-            300_000,
+            // At the current mainnet scale, we should assume most levels of the (hexary) JMT nodes
+            // in cache, hence target charging 1-2 4k-sized pages for each read. Notice the cost
+            // of seeking for the leaf node is covered by the first page of the "value size fee"
+            // (storage_io_per_state_byte_read) defined below.
+            800_000,
         ],
         [
             storage_io_per_state_byte_read: InternalGasPerByte,
             { 0..=9 => "load_data.per_byte", 10.. => "storage_io_per_state_byte_read"},
-            300,
+            // Notice in the latest IoPricing, bytes are charged at 4k intervals (even the smallest
+            // read will be charged for 4KB) to reflect the assumption that every roughly 4k bytes
+            // might require a separate random IO upon the FS.
+            100,
         ],
         [load_data_failure: InternalGas, "load_data.failure", 0],
         // Gas parameters for writing data to storage.
@@ -110,7 +117,7 @@ crate::gas_schedule::macros::define_gas_parameters!(
         ],
         [memory_quota: AbstractValueSize, { 1.. => "memory_quota" }, 10_000_000],
         [
-            free_write_bytes_quota: NumBytes,
+            legacy_free_write_bytes_quota: NumBytes,
             { 5.. => "free_write_bytes_quota" },
             1024, // 1KB free per state write
         ],
@@ -211,7 +218,7 @@ impl TransactionGasParameters {
     pub fn storage_fee_for_bytes(&self, key: &StateKey, op_size: &WriteOpSize) -> Fee {
         if let Some(value_size) = op_size.write_len() {
             let size = NumBytes::new(key.size() as u64) + NumBytes::new(value_size);
-            if let Some(excess) = size.checked_sub(self.free_write_bytes_quota) {
+            if let Some(excess) = size.checked_sub(self.legacy_free_write_bytes_quota) {
                 return excess * self.storage_fee_per_excess_state_byte;
             }
         }

aptos-move/aptos-vm-types/src/storage/io_pricing.rs

@@ -120,7 +120,7 @@ impl IoPricingV2 {
             0 => unreachable!("PricingV2 not applicable for feature version 0"),
             1..=2 => 0.into(),
             3..=4 => 1024.into(),
-            5.. => gas_params.vm.txn.free_write_bytes_quota,
+            5.. => gas_params.vm.txn.legacy_free_write_bytes_quota,
         }
     }
 
@@ -167,24 +167,43 @@ impl IoPricingV2 {
 #[derive(Debug, Clone)]
 pub struct IoPricingV3 {
     pub feature_version: u64,
-    pub free_write_bytes_quota: NumBytes,
+    pub legacy_free_write_bytes_quota: NumBytes,
 }
 
 impl IoPricingV3 {
+    fn read_size(&self, loaded: NumBytes) -> NumBytes {
+        if self.feature_version >= 12 {
+            // round up bytes to whole pages
+
+            const PAGE_SIZE: u64 = 4096;
+            let loaded_u64: u64 = loaded.into();
+            let r = loaded_u64 % PAGE_SIZE;
+            let rounded_up = loaded_u64 + if r == 0 { 0 } else { PAGE_SIZE - r };
+            NumBytes::new(rounded_up)
+        } else {
+            loaded
+        }
+    }
+
     fn calculate_read_gas(
         &self,
         loaded: NumBytes,
     ) -> impl GasExpression<VMGasParameters, Unit = InternalGasUnit> {
-        STORAGE_IO_PER_STATE_SLOT_READ * NumArgs::from(1) + STORAGE_IO_PER_STATE_BYTE_READ * loaded
+        STORAGE_IO_PER_STATE_SLOT_READ * NumArgs::from(1)
+            + STORAGE_IO_PER_STATE_BYTE_READ * self.read_size(loaded)
     }
 
     fn write_op_size(&self, key: &StateKey, value_size: u64) -> NumBytes {
         let key_size = NumBytes::new(key.size() as u64);
         let value_size = NumBytes::new(value_size);
+        let size = key_size + value_size;
 
-        (key_size + value_size)
-            .checked_sub(self.free_write_bytes_quota)
-            .unwrap_or(NumBytes::zero())
+        if self.feature_version >= 12 {
+            size.checked_sub(self.legacy_free_write_bytes_quota)
+                .unwrap_or(NumBytes::zero())
+        } else {
+            size
+        }
     }
 
     fn io_gas_per_write(
@@ -232,7 +251,7 @@ impl IoPricing {
             },
             10.. => V3(IoPricingV3 {
                 feature_version,
-                free_write_bytes_quota: gas_params.vm.txn.free_write_bytes_quota,
+                legacy_free_write_bytes_quota: gas_params.vm.txn.legacy_free_write_bytes_quota,
             }),
         }
     }

aptos-move/aptos-vm-types/src/storage/mod.rs

@@ -38,7 +38,7 @@ impl StorageGasParameters {
         Self {
             io_pricing: IoPricing::V3(IoPricingV3 {
                 feature_version: LATEST_GAS_FEATURE_VERSION,
-                free_write_bytes_quota,
+                legacy_free_write_bytes_quota: free_write_bytes_quota,
             }),
             change_set_configs: ChangeSetConfigs::unlimited_at_gas_feature_version(
                 LATEST_GAS_FEATURE_VERSION,

aptos-move/e2e-move-tests/src/tests/per_category_gas_limits.rs

@@ -91,7 +91,7 @@ fn io_limit_reached_by_new_bytes() {
         // Allow 10 value bytes charged at most.
         gas_params.vm.txn.max_io_gas = 110_000_000.into();
         // Make the key bytes free, only play around value sizes.
-        gas_params.vm.txn.free_write_bytes_quota = state_key_size();
+        gas_params.vm.txn.legacy_free_write_bytes_quota = state_key_size();
     });
 
     test_create_multiple_items(&mut h, &acc, |status| {
@@ -112,7 +112,7 @@ fn storage_limit_reached_by_new_bytes() {
         // Allow 10 value bytes charged at most.
         gas_params.vm.txn.max_storage_fee = 11_000_000.into();
         // Make the key bytes free, only play around value sizes.
-        gas_params.vm.txn.free_write_bytes_quota = state_key_size();
+        gas_params.vm.txn.legacy_free_write_bytes_quota = state_key_size();
     });
 
     test_create_multiple_items(&mut h, &acc, |status| {
@@ -134,7 +134,7 @@ fn out_of_gas_while_charging_write_gas() {
         // Bump max gas allowed
         gas_params.vm.txn.maximum_number_of_gas_units = 1_000_000_000.into();
         // Make the key bytes free, only play around value sizes.
-        gas_params.vm.txn.free_write_bytes_quota = state_key_size();
+        gas_params.vm.txn.legacy_free_write_bytes_quota = state_key_size();
     });
     // Allow 10 value bytes charged at most. Notice this is in external units.
     h.set_max_gas_per_txn(110_000);
@@ -156,7 +156,7 @@ fn out_of_gas_while_charging_storage_fee() {
         // Bump max gas allowed
         gas_params.vm.txn.maximum_number_of_gas_units = 1_000_000_000.into();
         // Make the key bytes free, only play around value sizes.
-        gas_params.vm.txn.free_write_bytes_quota = state_key_size();
+        gas_params.vm.txn.legacy_free_write_bytes_quota = state_key_size();
     });
     // Allow 10 value bytes charged at most. Notice this is in external units,
     //   which is 1/100x octas or 1Mx internal units.

aptos-move/e2e-testsuite/src/tests/failed_transaction_tests.rs

@@ -40,7 +40,7 @@ fn failed_transaction_cleanup_test() {
 
     let gas_params = AptosGasParameters::zeros();
     let storage_gas_params =
-        StorageGasParameters::unlimited(gas_params.vm.txn.free_write_bytes_quota);
+        StorageGasParameters::unlimited(gas_params.vm.txn.legacy_free_write_bytes_quota);
 
     let change_set_configs = storage_gas_params.change_set_configs.clone();
 

aptos-move/framework/table-natives/src/lib.rs

@@ -287,7 +287,17 @@ fn charge_load_cost(
 
     match loaded {
         Some(Some(num_bytes)) => {
-            context.charge(COMMON_LOAD_BASE_NEW + COMMON_LOAD_PER_BYTE * num_bytes)
+            if context.gas_feature_version() >= 12 {
+                // round up bytes to whole pages
+                const PAGE_SIZE: u64 = 4096;
+                let loaded_u64: u64 = num_bytes.into();
+                let r = loaded_u64 % PAGE_SIZE;
+                let rounded_up = loaded_u64 + if r == 0 { 0 } else { PAGE_SIZE - r };
+                context
+                    .charge(COMMON_LOAD_BASE_NEW + COMMON_LOAD_PER_BYTE * NumBytes::new(rounded_up))
+            } else {
+                context.charge(COMMON_LOAD_BASE_NEW + COMMON_LOAD_PER_BYTE * num_bytes)
+            }
         },
         Some(None) => context.charge(COMMON_LOAD_BASE_NEW + COMMON_LOAD_FAILURE),
         None => Ok(()),