Merge branch 'alexuta/double_query_threads' into 'master'

[RUN-670] Double number of queries on application subnets

The file backed allocator is enabled now only on application subnets (excluding system and verified application subnets). This means that on application subnets we can now double the total number of query threads because in the worst-case scenario, they will still fit in memory due to the file-backed allocator. 

See merge request dfinity-lab/public/ic!12897

rs/execution_environment/src/lib.rs

@@ -140,8 +140,18 @@ impl ExecutionServices {
             Arc::clone(&cycles_account_manager),
         ));
 
+        // If this is not a system or verified subnet we can double the
+        // number of query execution threads total because the file-backed
+        // allocator is enabled on these subnets and thus we can fit more
+        // concurrent queries in memory.
+        // TODO: remove this once the file-backed allocator is enabled on all subnets.
+        let query_execution_threads_total = if own_subnet_type == SubnetType::Application {
+            config.query_execution_threads_total * 2
+        } else {
+            config.query_execution_threads_total
+        };
         let query_scheduler = QueryScheduler::new(
-            config.query_execution_threads_total,
+            query_execution_threads_total,
             config.query_execution_threads_per_canister,
             config.query_scheduling_time_slice_per_canister,
             metrics_registry,