feat: Add metric to CallTracer for calculating maximum depth of the c…

…alls (#535) ## What ❔ Add metric to CallTracer for calculating maximum depth of the calls ## Why ❔ We need to know what our limits are. ## Checklist - [x] PR title corresponds to the body of PR (we generate changelog entries from PRs). - [ ] Tests for the changes have been added / updated. - [x] Documentation comments have been added / updated. - [x] Code has been formatted via `zk fmt` and `zk lint`.
matter-labs · Dec 4, 2023 · 19c84ce · 19c84ce
1 parent c594323
commit 19c84ce
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Showing 5 changed files with 77 additions and 30 deletions.
diff --git a/core/lib/multivm/src/tracers/call_tracer/metrics.rs b/core/lib/multivm/src/tracers/call_tracer/metrics.rs
@@ -0,0 +1,15 @@
+use vise::{Buckets, Histogram, Metrics};
+
+#[derive(Debug, Metrics)]
+#[metrics(prefix = "vm_call_tracer")]
+pub struct CallMetrics {
+    /// Maximum call stack depth during the execution of the transaction.
+    #[metrics(buckets = Buckets::exponential(1.0..=64.0, 2.0))]
+    pub call_stack_depth: Histogram<usize>,
+    /// Maximum number of near calls during the execution of the transaction.
+    #[metrics(buckets = Buckets::exponential(1.0..=64.0, 2.0))]
+    pub max_near_calls: Histogram<usize>,
+}
+
+#[vise::register]
+pub static CALL_METRICS: vise::Global<CallMetrics> = vise::Global::new();
diff --git a/core/lib/multivm/src/tracers/call_tracer/mod.rs b/core/lib/multivm/src/tracers/call_tracer/mod.rs
@@ -1,7 +1,9 @@
+use crate::tracers::call_tracer::metrics::CALL_METRICS;
 use once_cell::sync::OnceCell;
 use std::sync::Arc;
 use zksync_types::vm_trace::Call;
 
+mod metrics;
 pub mod vm_latest;
 pub mod vm_refunds_enhancement;
 pub mod vm_virtual_blocks;
@@ -10,19 +12,32 @@ pub mod vm_virtual_blocks;
 pub struct CallTracer {
     stack: Vec<FarcallAndNearCallCount>,
     result: Arc<OnceCell<Vec<Call>>>,
+
+    max_stack_depth: usize,
+    max_near_calls: usize,
 }
 
 #[derive(Debug, Clone)]
 struct FarcallAndNearCallCount {
     farcall: Call,
     near_calls_after: usize,
+    stack_depth_on_prefix: usize,
+}
+
+impl Drop for CallTracer {
+    fn drop(&mut self) {
+        CALL_METRICS.call_stack_depth.observe(self.max_stack_depth);
+        CALL_METRICS.max_near_calls.observe(self.max_near_calls);
+    }
 }
 
 impl CallTracer {
     pub fn new(result: Arc<OnceCell<Vec<Call>>>) -> Self {
         Self {
             stack: vec![],
             result,
+            max_stack_depth: 0,
+            max_near_calls: 0,
         }
     }
 
@@ -38,4 +53,35 @@ impl CallTracer {
         let cell = self.result.as_ref();
         cell.set(result).unwrap();
     }
+
+    fn push_call_and_update_stats(&mut self, farcall: Call, near_calls_after: usize) {
+        let stack_depth = self
+            .stack
+            .last()
+            .map(|x| x.stack_depth_on_prefix)
+            .unwrap_or(0);
+
+        let depth_on_prefix = stack_depth + 1 + near_calls_after;
+
+        let call = FarcallAndNearCallCount {
+            farcall,
+            near_calls_after,
+            stack_depth_on_prefix: depth_on_prefix,
+        };
+
+        self.stack.push(call);
+
+        self.max_stack_depth = self.max_stack_depth.max(depth_on_prefix);
+        self.max_near_calls = self.max_near_calls.max(near_calls_after);
+    }
+
+    fn increase_near_call_count(&mut self) {
+        if let Some(last) = self.stack.last_mut() {
+            last.near_calls_after += 1;
+            last.stack_depth_on_prefix += 1;
+
+            self.max_near_calls = self.max_near_calls.max(last.near_calls_after);
+            self.max_stack_depth = self.max_stack_depth.max(last.stack_depth_on_prefix);
+        }
+    }
 }
diff --git a/core/lib/multivm/src/tracers/call_tracer/vm_latest/mod.rs b/core/lib/multivm/src/tracers/call_tracer/vm_latest/mod.rs
@@ -15,7 +15,7 @@ use crate::interface::{
     tracer::VmExecutionStopReason, traits::tracers::dyn_tracers::vm_1_4_0::DynTracer,
     VmRevertReason,
 };
-use crate::tracers::call_tracer::{CallTracer, FarcallAndNearCallCount};
+use crate::tracers::call_tracer::CallTracer;
 use crate::vm_latest::{BootloaderState, HistoryMode, SimpleMemory, VmTracer, ZkSyncVmState};
 
 impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
@@ -28,9 +28,7 @@ impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
     ) {
         match data.opcode.variant.opcode {
             Opcode::NearCall(_) => {
-                if let Some(last) = self.stack.last_mut() {
-                    last.near_calls_after += 1;
-                }
+                self.increase_near_call_count();
             }
             Opcode::FarCall(far_call) => {
                 // We use parent gas for properly calculating gas used in the trace.
@@ -51,10 +49,7 @@ impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
                 };
 
                 self.handle_far_call_op_code_latest(state, memory, &mut current_call);
-                self.stack.push(FarcallAndNearCallCount {
-                    farcall: current_call,
-                    near_calls_after: 0,
-                });
+                self.push_call_and_update_stats(current_call, 0);
             }
             Opcode::Ret(ret_code) => {
                 self.handle_ret_op_code_latest(state, memory, ret_code);
@@ -187,7 +182,7 @@ impl CallTracer {
 
         if current_call.near_calls_after > 0 {
             current_call.near_calls_after -= 1;
-            self.stack.push(current_call);
+            self.push_call_and_update_stats(current_call.farcall, current_call.near_calls_after);
             return;
         }
 
@@ -203,7 +198,7 @@ impl CallTracer {
         if let Some(parent_call) = self.stack.last_mut() {
             parent_call.farcall.calls.push(current_call.farcall);
         } else {
-            self.stack.push(current_call);
+            self.push_call_and_update_stats(current_call.farcall, current_call.near_calls_after);
         }
     }
 }
diff --git a/core/lib/multivm/src/tracers/call_tracer/vm_refunds_enhancement/mod.rs b/core/lib/multivm/src/tracers/call_tracer/vm_refunds_enhancement/mod.rs
@@ -15,7 +15,7 @@ use crate::interface::{
     tracer::VmExecutionStopReason, traits::tracers::dyn_tracers::vm_1_3_3::DynTracer,
     VmRevertReason,
 };
-use crate::tracers::call_tracer::{CallTracer, FarcallAndNearCallCount};
+use crate::tracers::call_tracer::CallTracer;
 use crate::vm_refunds_enhancement::{
     BootloaderState, HistoryMode, SimpleMemory, VmTracer, ZkSyncVmState,
 };
@@ -30,9 +30,7 @@ impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
     ) {
         match data.opcode.variant.opcode {
             Opcode::NearCall(_) => {
-                if let Some(last) = self.stack.last_mut() {
-                    last.near_calls_after += 1;
-                }
+                self.increase_near_call_count();
             }
             Opcode::FarCall(far_call) => {
                 // We use parent gas for properly calculating gas used in the trace.
@@ -53,10 +51,8 @@ impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
                 };
 
                 self.handle_far_call_op_code_refunds_enhancement(state, memory, &mut current_call);
-                self.stack.push(FarcallAndNearCallCount {
-                    farcall: current_call,
-                    near_calls_after: 0,
-                });
+
+                self.push_call_and_update_stats(current_call, 0);
             }
             Opcode::Ret(ret_code) => {
                 self.handle_ret_op_code_refunds_enhancement(state, memory, ret_code);
@@ -189,7 +185,7 @@ impl CallTracer {
 
         if current_call.near_calls_after > 0 {
             current_call.near_calls_after -= 1;
-            self.stack.push(current_call);
+            self.push_call_and_update_stats(current_call.farcall, current_call.near_calls_after);
             return;
         }
 
@@ -205,7 +201,7 @@ impl CallTracer {
         if let Some(parent_call) = self.stack.last_mut() {
             parent_call.farcall.calls.push(current_call.farcall);
         } else {
-            self.stack.push(current_call);
+            self.push_call_and_update_stats(current_call.farcall, current_call.near_calls_after);
         }
     }
 }
diff --git a/core/lib/multivm/src/tracers/call_tracer/vm_virtual_blocks/mod.rs b/core/lib/multivm/src/tracers/call_tracer/vm_virtual_blocks/mod.rs
@@ -12,7 +12,7 @@ use zksync_types::U256;
 use crate::interface::{
     dyn_tracers::vm_1_3_3::DynTracer, VmExecutionResultAndLogs, VmRevertReason,
 };
-use crate::tracers::call_tracer::{CallTracer, FarcallAndNearCallCount};
+use crate::tracers::call_tracer::CallTracer;
 use crate::vm_virtual_blocks::{
     ExecutionEndTracer, ExecutionProcessing, HistoryMode, SimpleMemory, VmTracer,
 };
@@ -27,9 +27,7 @@ impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
     ) {
         match data.opcode.variant.opcode {
             Opcode::NearCall(_) => {
-                if let Some(last) = self.stack.last_mut() {
-                    last.near_calls_after += 1;
-                }
+                self.increase_near_call_count();
             }
             Opcode::FarCall(far_call) => {
                 // We use parent gas for properly calculating gas used in the trace.
@@ -50,10 +48,7 @@ impl<S, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CallTracer {
                 };
 
                 self.handle_far_call_op_code_virtual_blocks(state, data, memory, &mut current_call);
-                self.stack.push(FarcallAndNearCallCount {
-                    farcall: current_call,
-                    near_calls_after: 0,
-                });
+                self.push_call_and_update_stats(current_call, 0);
             }
             Opcode::Ret(ret_code) => {
                 self.handle_ret_op_code_virtual_blocks(state, data, memory, ret_code);
@@ -187,7 +182,7 @@ impl CallTracer {
 
         if current_call.near_calls_after > 0 {
             current_call.near_calls_after -= 1;
-            self.stack.push(current_call);
+            self.push_call_and_update_stats(current_call.farcall, current_call.near_calls_after);
             return;
         }
 
@@ -203,7 +198,7 @@ impl CallTracer {
         if let Some(parent_call) = self.stack.last_mut() {
             parent_call.farcall.calls.push(current_call.farcall);
         } else {
-            self.stack.push(current_call);
+            self.push_call_and_update_stats(current_call.farcall, current_call.near_calls_after);
         }
     }
 }