Don't add markers for unknown ETW events

samply/src/windows/etw_gecko.rs

@@ -29,6 +29,8 @@ pub fn profile_pid_from_etl_file(context: &mut ProfileContext, etl_file: &Path)
 
     let mut core_clr_context = coreclr::CoreClrContext::new();
 
+    let markers_for_unknown_events = false; // TODO allow specifying this on command line
+
     // Make a dummy TimestampConverter. Once we've parsed the header, this will have correct values.
 
     let result = open_trace(etl_file, |e| {

samply/src/windows/profile_context.rs

@@ -253,6 +253,9 @@ pub struct ProfileContext {
 
     timestamp_converter: TimestampConverter,
     event_timestamps_are_qpc: bool,
+
+    // If true, will convert unhandled events to markers
+    unknown_events_to_markers: bool,
 }
 
 impl ProfileContext {
@@ -297,6 +300,7 @@ impl ProfileContext {
                 raw_to_ns_factor: 1,
             },
             event_timestamps_are_qpc: false,
+            unknown_events_to_markers: false,
         }
     }
 
@@ -1480,6 +1484,10 @@ impl ProfileContext {
         task_and_op: &str,
         stringified_properties: String,
     ) {
+        if !self.unknown_events_to_markers {
+            return;
+        }
+
         let Some(thread) = self.threads.get_mut(&tid) else {
             return;
         };