Add some perf events/data for tiered compilation (#24607)

Add some perf events/data for tiered compilation

New events:
- `Settings` - Sent when TC is enabled
  - `Flags` - Currently indicates whether QuickJit and QuickJitForLoops are enabled
- `Pause` - Sent when TC is paused (due to a new method being called for the first time)
- `Resume` - Sent when TC resumes
  - `NewMethodCount` - Number of methods called for the first time while tiering was paused
- `BackgroundJitStart` - Sent when starting to JIT methods in the background
  - `PendingMethodCount` - Number of methods currently scheduled for background JIT
- `BackgroundJitStop` - Sent when background jitting stops
  - `PendingMethodCount` - Same as above. When 0, background jitting has completed.
  - `JittedMethodCount` - Number of methods jitted in the background since the previous BackgroundJitStart event on the same thread

Miscellaneous:
- Updated method JIT events to include the optimization tier
- Added a couple more cases where tiered compilation is disabled for methods that have JIT optimization disabled for some reason
- Renamed `Duration` field of the new version of the `ContentionEnd` to `DurationNs` to indicate the units of time
- Added `OptimizationTierOptimized` to `NativeCodeVersion::OptimizationTier` to distinguish it from `OptimizationTier1`. `OptimizationTierOptimized` is now used for methods that QuickJit is disabled for, and does not send the tier 1 flag.
  - For info about the code being generated by the JIT, added info to `PrepareCodeConfig` and stored a pointer to it on the thread object for the current JIT invocation. Info is updated in `PrepareCodeConfig` and used for updating the tier on the code version and for sending the ETL event.
  - If the JIT decides to use MinOpt when `MethodDesc::IsJitOptimizationDisabled()` is false, the info is not stored. The runtime method event will reflect the JIT's choice, the rundown event will not.
- Updated to show optimization tiers in SOS similarly to PerfView

3 files changed, 25 insertions, 19 deletions

diff --git a/src/jit/compiler.cpp b/src/jit/compiler.cpp
index 4c4a90d937..25249e19bb 100644
--- a/src/jit/compiler.cpp
+++ b/src/jit/compiler.cpp
@@ -4050,6 +4050,13 @@ _SetMinOpts:
     // Set the MinOpts value
     opts.SetMinOpts(theMinOptsValue);
 
+    // Notify the VM if MinOpts is being used when not requested
+    if (theMinOptsValue && !compIsForInlining() && !opts.jitFlags->IsSet(JitFlags::JIT_FLAG_TIER0) &&
+        !opts.jitFlags->IsSet(JitFlags::JIT_FLAG_MIN_OPT) && !opts.compDbgCode)
+    {
+        info.compCompHnd->setMethodAttribs(info.compMethodHnd, CORINFO_FLG_SWITCHED_TO_MIN_OPT);
+    }
+
 #ifdef DEBUG
     if (verbose && !compIsForInlining())
     {
@@ -5949,14 +5956,14 @@ int Compiler::compCompileHelper(CORINFO_MODULE_HANDLE            classPtr,
     }
 
 #ifdef FEATURE_CORECLR
-    if (fgHasBackwardJump && (info.compFlags & CORINFO_FLG_DISABLE_TIER0_FOR_LOOPS) != 0 && fgCanSwitchToTier1())
+    if (fgHasBackwardJump && (info.compFlags & CORINFO_FLG_DISABLE_TIER0_FOR_LOOPS) != 0 && fgCanSwitchToOptimized())
 #else // !FEATURE_CORECLR
     // We may want to use JitConfig value here to support DISABLE_TIER0_FOR_LOOPS
     if (fgHasBackwardJump && fgCanSwitchToTier1())
 #endif
     {
         // Method likely has a loop, switch to the OptimizedTier to avoid spending too much time running slower code
-        fgSwitchToTier1();
+        fgSwitchToOptimized();
     }
 
     compSetOptimizationLevel();
diff --git a/src/jit/compiler.h b/src/jit/compiler.h
index 1db70d1612..c73ca30c16 100644
--- a/src/jit/compiler.h
+++ b/src/jit/compiler.h
@@ -5105,8 +5105,8 @@ protected:
 
     bool fgHasBackwardJump;
 
-    bool fgCanSwitchToTier1();
-    void fgSwitchToTier1();
+    bool fgCanSwitchToOptimized();
+    void fgSwitchToOptimized();
 
     bool fgMayExplicitTailCall();
 
diff --git a/src/jit/flowgraph.cpp b/src/jit/flowgraph.cpp
index d8b12188ec..62d958fa88 100644
--- a/src/jit/flowgraph.cpp
+++ b/src/jit/flowgraph.cpp
@@ -4253,10 +4253,10 @@ private:
 };
 
 //------------------------------------------------------------------------
-// fgCanSwitchToTier1: Determines if conditions are met to allow switching the opt level to tier 1
+// fgCanSwitchToOptimized: Determines if conditions are met to allow switching the opt level to optimized
 //
 // Return Value:
-//    True if the opt level may be switched to tier 1, false otherwise
+//    True if the opt level may be switched from tier 0 to optimized, false otherwise
 //
 // Assumptions:
 //    - compInitOptions() has been called
@@ -4266,7 +4266,7 @@ private:
 //    This method is to be called at some point before compSetOptimizationLevel() to determine if the opt level may be
 //    changed based on information gathered in early phases.
 
-bool Compiler::fgCanSwitchToTier1()
+bool Compiler::fgCanSwitchToOptimized()
 {
     bool result = opts.jitFlags->IsSet(JitFlags::JIT_FLAG_TIER0) && !opts.jitFlags->IsSet(JitFlags::JIT_FLAG_MIN_OPT) &&
                   !opts.compDbgCode && !compIsForInlining();
@@ -4281,28 +4281,27 @@ bool Compiler::fgCanSwitchToTier1()
 }
 
 //------------------------------------------------------------------------
-// fgSwitchToTier1: Switch the opt level to tier 1
+// fgSwitchToOptimized: Switch the opt level from tier 0 to optimized
 //
 // Assumptions:
-//    - fgCanSwitchToTier1() is true
+//    - fgCanSwitchToOptimized() is true
 //    - compSetOptimizationLevel() has not been called
 //
 // Notes:
-//    This method is to be called at some point before compSetOptimizationLevel() to switch the opt level to tier 1
+//    This method is to be called at some point before compSetOptimizationLevel() to switch the opt level to optimized
 //    based on information gathered in early phases.
 
-void Compiler::fgSwitchToTier1()
+void Compiler::fgSwitchToOptimized()
 {
-    assert(fgCanSwitchToTier1());
+    assert(fgCanSwitchToOptimized());
 
-    // Switch to tier 1 and re-init options
+    // Switch to optimized and re-init options
     assert(opts.jitFlags->IsSet(JitFlags::JIT_FLAG_TIER0));
     opts.jitFlags->Clear(JitFlags::JIT_FLAG_TIER0);
-    opts.jitFlags->Set(JitFlags::JIT_FLAG_TIER1);
     compInitOptions(opts.jitFlags);
 
     // Notify the VM of the change
-    info.compCompHnd->setMethodAttribs(info.compMethodHnd, CORINFO_FLG_SWITCHED_TO_TIER1);
+    info.compCompHnd->setMethodAttribs(info.compMethodHnd, CORINFO_FLG_SWITCHED_TO_OPTIMIZED);
 }
 
 //------------------------------------------------------------------------
@@ -5605,12 +5604,12 @@ unsigned Compiler::fgMakeBasicBlocks(const BYTE* codeAddr, IL_OFFSET codeSize, F
 #endif // !FEATURE_CORECLR && _TARGET_AMD64_
                     }
 
-                    if (fgCanSwitchToTier1() && fgMayExplicitTailCall())
+                    if (fgCanSwitchToOptimized() && fgMayExplicitTailCall())
                     {
                         // Method has an explicit tail call that may run like a loop or may not be generated as a tail
-                        // call in tier 0, switch to tier 1 to avoid spending too much time running slower code and to
-                        // avoid stack overflow from recursion
-                        fgSwitchToTier1();
+                        // call in tier 0, switch to optimized to avoid spending too much time running slower code and
+                        // to avoid stack overflow from recursion
+                        fgSwitchToOptimized();
                     }
 
 #if !defined(FEATURE_CORECLR) && defined(_TARGET_AMD64_)