Rollup merge of #59915 - michaelwoerister:sp-event-filters-1, r=wesleywiser

Implement event filtering for self-profiler.

This is a first sketch for event filtering in the self-profiler, something that we'll want in order to keep profiling overhead low in the common case. The PR contains the commits from https://github.com/rust-lang/rust/pull/59515 and, for the moment, is meant for performance testing.

r? @wesleywiser

3 files changed, 97 insertions, 28 deletions

diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index dc1ceaf69f0..97a1c83dbff 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -1467,6 +1467,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "inject the given attribute in the crate"),
     self_profile: bool = (false, parse_bool, [UNTRACKED],
         "run the self profiler and output the raw event data"),
+    self_profile_events: Option<Vec<String>> = (None, parse_opt_comma_list, [UNTRACKED],
+        "specifies which kinds of events get recorded by the self profiler"),
     emit_stack_sizes: bool = (false, parse_bool, [UNTRACKED],
         "emits a section containing stack size metadata"),
     plt: Option<bool> = (None, parse_opt_bool, [TRACKED],
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index eed516a4381..eecd5cba6d3 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -1138,7 +1138,7 @@ fn build_session_(
 ) -> Session {
     let self_profiler =
         if sopts.debugging_opts.self_profile {
-            let profiler = SelfProfiler::new();
+            let profiler = SelfProfiler::new(&sopts.debugging_opts.self_profile_events);
             match profiler {
                 Ok(profiler) => {
                     crate::ty::query::QueryName::register_with_profiler(&profiler);
diff --git a/src/librustc/util/profiling.rs b/src/librustc/util/profiling.rs
index aabf9a401c6..585970e64df 100644
--- a/src/librustc/util/profiling.rs
+++ b/src/librustc/util/profiling.rs
@@ -27,26 +27,42 @@ pub enum ProfileCategory {
     Other,
 }
 
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub enum ProfilerEvent {
-    QueryStart { query_name: &'static str, category: ProfileCategory, time: u64 },
-    QueryEnd { query_name: &'static str, category: ProfileCategory, time: u64 },
-    GenericActivityStart { category: ProfileCategory, label: Cow<'static, str>, time: u64 },
-    GenericActivityEnd { category: ProfileCategory, label: Cow<'static, str>, time: u64 },
-    IncrementalLoadResultStart { query_name: &'static str, time: u64 },
-    IncrementalLoadResultEnd { query_name: &'static str, time: u64 },
-    QueryCacheHit { query_name: &'static str, category: ProfileCategory, time: u64 },
-    QueryCount { query_name: &'static str, category: ProfileCategory, count: usize, time: u64 },
-    QueryBlockedStart { query_name: &'static str, category: ProfileCategory, time: u64 },
-    QueryBlockedEnd { query_name: &'static str, category: ProfileCategory, time: u64 },
+bitflags! {
+    struct EventFilter: u32 {
+        const GENERIC_ACTIVITIES = 1 << 0;
+        const QUERY_PROVIDERS    = 1 << 1;
+        const QUERY_CACHE_HITS   = 1 << 2;
+        const QUERY_BLOCKED      = 1 << 3;
+        const INCR_CACHE_LOADS   = 1 << 4;
+
+        const DEFAULT = Self::GENERIC_ACTIVITIES.bits |
+                        Self::QUERY_PROVIDERS.bits |
+                        Self::QUERY_BLOCKED.bits |
+                        Self::INCR_CACHE_LOADS.bits;
+
+        // empty() and none() aren't const-fns unfortunately
+        const NONE = 0;
+        const ALL  = !Self::NONE.bits;
+    }
 }
 
+const EVENT_FILTERS_BY_NAME: &[(&str, EventFilter)] = &[
+    ("none", EventFilter::NONE),
+    ("all", EventFilter::ALL),
+    ("generic-activity", EventFilter::GENERIC_ACTIVITIES),
+    ("query-provider", EventFilter::QUERY_PROVIDERS),
+    ("query-cache-hit", EventFilter::QUERY_CACHE_HITS),
+    ("query-blocked" , EventFilter::QUERY_BLOCKED),
+    ("incr-cache-load", EventFilter::INCR_CACHE_LOADS),
+];
+
 fn thread_id_to_u64(tid: ThreadId) -> u64 {
     unsafe { mem::transmute::<ThreadId, u64>(tid) }
 }
 
 pub struct SelfProfiler {
     profiler: Profiler,
+    event_filter_mask: EventFilter,
     query_event_kind: StringId,
     generic_activity_event_kind: StringId,
     incremental_load_result_event_kind: StringId,
@@ -55,7 +71,7 @@ pub struct SelfProfiler {
 }
 
 impl SelfProfiler {
-    pub fn new() -> Result<SelfProfiler, Box<dyn Error>> {
+    pub fn new(event_filters: &Option<Vec<String>>) -> Result<SelfProfiler, Box<dyn Error>> {
         let filename = format!("pid-{}.rustc_profile", process::id());
         let path = std::path::Path::new(&filename);
         let profiler = Profiler::new(path)?;
@@ -66,8 +82,38 @@ impl SelfProfiler {
         let query_blocked_event_kind = profiler.alloc_string("QueryBlocked");
         let query_cache_hit_event_kind = profiler.alloc_string("QueryCacheHit");
 
+        let mut event_filter_mask = EventFilter::empty();
+
+        if let Some(ref event_filters) = *event_filters {
+            let mut unknown_events = vec![];
+            for item in event_filters {
+                if let Some(&(_, mask)) = EVENT_FILTERS_BY_NAME.iter()
+                                                               .find(|&(name, _)| name == item) {
+                    event_filter_mask |= mask;
+                } else {
+                    unknown_events.push(item.clone());
+                }
+            }
+
+            // Warn about any unknown event names
+            if unknown_events.len() > 0 {
+                unknown_events.sort();
+                unknown_events.dedup();
+
+                warn!("Unknown self-profiler events specified: {}. Available options are: {}.",
+                    unknown_events.join(", "),
+                    EVENT_FILTERS_BY_NAME.iter()
+                                         .map(|&(name, _)| name.to_string())
+                                         .collect::<Vec<_>>()
+                                         .join(", "));
+            }
+        } else {
+            event_filter_mask = EventFilter::DEFAULT;
+        }
+
         Ok(SelfProfiler {
             profiler,
+            event_filter_mask,
             query_event_kind,
             generic_activity_event_kind,
             incremental_load_result_event_kind,
@@ -86,7 +132,6 @@ impl SelfProfiler {
 
     pub fn register_query_name(&self, query_name: QueryName) {
         let id = SelfProfiler::get_query_name_string_id(query_name);
-
         self.profiler.alloc_string_with_reserved_id(id, query_name.as_str());
     }
 
@@ -95,7 +140,9 @@ impl SelfProfiler {
         &self,
         label: impl Into<Cow<'static, str>>,
     ) {
-        self.record(&label.into(), self.generic_activity_event_kind, TimestampKind::Start);
+        if self.event_filter_mask.contains(EventFilter::GENERIC_ACTIVITIES) {
+            self.record(&label.into(), self.generic_activity_event_kind, TimestampKind::Start);
+        }
     }
 
     #[inline]
@@ -103,46 +150,66 @@ impl SelfProfiler {
         &self,
         label: impl Into<Cow<'static, str>>,
     ) {
-        self.record(&label.into(), self.generic_activity_event_kind, TimestampKind::End);
+        if self.event_filter_mask.contains(EventFilter::GENERIC_ACTIVITIES) {
+            self.record(&label.into(), self.generic_activity_event_kind, TimestampKind::End);
+        }
     }
 
     #[inline]
     pub fn record_query_hit(&self, query_name: QueryName) {
-        self.record_query(query_name, self.query_cache_hit_event_kind, TimestampKind::Instant);
+        if self.event_filter_mask.contains(EventFilter::QUERY_CACHE_HITS) {
+            self.record_query(query_name, self.query_cache_hit_event_kind, TimestampKind::Instant);
+        }
     }
 
     #[inline]
     pub fn start_query(&self, query_name: QueryName) {
-        self.record_query(query_name, self.query_event_kind, TimestampKind::Start);
+        if self.event_filter_mask.contains(EventFilter::QUERY_PROVIDERS) {
+            self.record_query(query_name, self.query_event_kind, TimestampKind::Start);
+        }
     }
 
     #[inline]
     pub fn end_query(&self, query_name: QueryName) {
-        self.record_query(query_name, self.query_event_kind, TimestampKind::End);
+        if self.event_filter_mask.contains(EventFilter::QUERY_PROVIDERS) {
+            self.record_query(query_name, self.query_event_kind, TimestampKind::End);
+        }
     }
 
     #[inline]
     pub fn incremental_load_result_start(&self, query_name: QueryName) {
-        self.record_query(
-            query_name,
-            self.incremental_load_result_event_kind,
-            TimestampKind::Start
-        );
+        if self.event_filter_mask.contains(EventFilter::INCR_CACHE_LOADS) {
+            self.record_query(
+                query_name,
+                self.incremental_load_result_event_kind,
+                TimestampKind::Start
+            );
+        }
     }
 
     #[inline]
     pub fn incremental_load_result_end(&self, query_name: QueryName) {
-        self.record_query(query_name, self.incremental_load_result_event_kind, TimestampKind::End);
+        if self.event_filter_mask.contains(EventFilter::INCR_CACHE_LOADS) {
+            self.record_query(
+                query_name,
+                self.incremental_load_result_event_kind,
+                TimestampKind::End
+            );
+        }
     }
 
     #[inline]
     pub fn query_blocked_start(&self, query_name: QueryName) {
-        self.record_query(query_name, self.query_blocked_event_kind, TimestampKind::Start);
+        if self.event_filter_mask.contains(EventFilter::QUERY_BLOCKED) {
+            self.record_query(query_name, self.query_blocked_event_kind, TimestampKind::Start);
+        }
     }
 
     #[inline]
     pub fn query_blocked_end(&self, query_name: QueryName) {
-        self.record_query(query_name, self.query_blocked_event_kind, TimestampKind::End);
+        if self.event_filter_mask.contains(EventFilter::QUERY_BLOCKED) {
+            self.record_query(query_name, self.query_blocked_event_kind, TimestampKind::End);
+        }
     }
 
     #[inline]