Merge pull request #1510 from opentensor/ema-hotfix

Change update_moving_price() function

Author: sam0x17

.github/workflows/try-runtime.yml

@@ -9,6 +9,7 @@ env:
 jobs:
   check-devnet:
     name: check devnet
+    if: github.base_ref != 'main'
     runs-on: SubtensorCI
     steps:
       - name: Checkout sources
@@ -29,7 +30,7 @@ jobs:
 
   check-testnet:
     name: check testnet
-    # if: github.base_ref == 'testnet' || github.base_ref == 'devnet' || github.base_ref == 'main'
+    if: github.base_ref != 'main'
     runs-on: SubtensorCI
     steps:
       - name: Checkout sources

pallets/subtensor/src/staking/stake_utils.rs

@@ -56,26 +56,30 @@ impl<T: Config> Pallet<T> {
             SubnetMovingPrice::<T>::get(netuid)
         }
     }
+
     pub fn update_moving_price(netuid: u16) {
-        let blocks_since_registration = I96F32::saturating_from_num(
-            Self::get_current_block_as_u64().saturating_sub(NetworkRegisteredAt::<T>::get(netuid)),
-        );
+        let blocks_since_start_call = I96F32::saturating_from_num({
+            // We expect FirstEmissionBlockNumber to be set earlier, and we take the block when
+            // `start_call` was called (first block before FirstEmissionBlockNumber).
+            let start_call_block = FirstEmissionBlockNumber::<T>::get(netuid)
+                .unwrap_or_default()
+                .saturating_sub(1);
+
+            Self::get_current_block_as_u64().saturating_sub(start_call_block)
+        });
 
-        // Use halving time hyperparameter. The meaning of this parameter can be best explained under
-        // the assumption of a constant price and SubnetMovingAlpha == 0.5: It is how many blocks it
-        // will take in order for the distance between current EMA of price and current price to shorten
-        // by half.
         let halving_time = EMAPriceHalvingBlocks::<T>::get(netuid);
         let alpha: I96F32 =
-            SubnetMovingAlpha::<T>::get().saturating_mul(blocks_since_registration.safe_div(
-                blocks_since_registration.saturating_add(I96F32::saturating_from_num(halving_time)),
+            SubnetMovingAlpha::<T>::get().saturating_mul(blocks_since_start_call.safe_div(
+                blocks_since_start_call.saturating_add(I96F32::saturating_from_num(halving_time)),
             ));
         let minus_alpha: I96F32 = I96F32::saturating_from_num(1.0).saturating_sub(alpha);
         let current_price: I96F32 = alpha
             .saturating_mul(Self::get_alpha_price(netuid).min(I96F32::saturating_from_num(1.0)));
         let current_moving: I96F32 =
             minus_alpha.saturating_mul(Self::get_moving_alpha_price(netuid));
         let new_moving: I96F32 = current_price.saturating_add(current_moving);
+
         SubnetMovingPrice::<T>::insert(netuid, new_moving);
     }
 

pallets/subtensor/src/tests/coinbase.rs

@@ -191,7 +191,7 @@ fn test_coinbase_moving_prices() {
         SubnetAlphaIn::<Test>::insert(netuid, 1_000_000);
         SubnetMechanism::<Test>::insert(netuid, 1);
         SubnetMovingPrice::<Test>::insert(netuid, I96F32::from_num(1));
-        NetworkRegisteredAt::<Test>::insert(netuid, 1);
+        FirstEmissionBlockNumber::<Test>::insert(netuid, 1);
 
         // Updating the moving price keeps it the same.
         assert_eq!(
@@ -250,7 +250,7 @@ fn test_update_moving_price_initial() {
 
         // Registered recently
         System::set_block_number(510);
-        NetworkRegisteredAt::<Test>::insert(netuid, 500);
+        FirstEmissionBlockNumber::<Test>::insert(netuid, 500);
 
         SubtensorModule::update_moving_price(netuid);
 
@@ -275,7 +275,7 @@ fn test_update_moving_price_after_time() {
 
         // Registered long time ago
         System::set_block_number(144_000_500);
-        NetworkRegisteredAt::<Test>::insert(netuid, 500);
+        FirstEmissionBlockNumber::<Test>::insert(netuid, 500);
 
         SubtensorModule::update_moving_price(netuid);
 

runtime/src/lib.rs

@@ -207,7 +207,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
     //   `spec_version`, and `authoring_version` are the same between Wasm and native.
     // This value is set to 100 to notify Polkadot-JS App (https://polkadot.js.org/apps) to use
     //   the compatible custom types.
-    spec_version: 257,
+    spec_version: 258,
     impl_version: 1,
     apis: RUNTIME_API_VERSIONS,
     transaction_version: 1,