+//! # Rust Compiler Self-Profiling
+//!
+//! This module implements the basic framework for the compiler's self-
+//! profiling support. It provides the `SelfProfiler` type which enables
+//! recording "events". An event is something that starts and ends at a given
+//! point in time and has an ID and a kind attached to it. This allows for
+//! tracing the compiler's activity.
+//!
+//! Internally this module uses the custom tailored [measureme][mm] crate for
+//! efficiently recording events to disk in a compact format that can be
+//! post-processed and analyzed by the suite of tools in the `measureme`
+//! project. The highest priority for the tracing framework is on incurring as
+//! little overhead as possible.
+//!
+//!
+//! ## Event Overview
+//!
+//! Events have a few properties:
+//!
+//! - The `event_kind` designates the broad category of an event (e.g. does it
+//! correspond to the execution of a query provider or to loading something
+//! from the incr. comp. on-disk cache, etc).
+//! - The `event_id` designates the query invocation or function call it
+//! corresponds to, possibly including the query key or function arguments.
+//! - Each event stores the ID of the thread it was recorded on.
+//! - The timestamp stores beginning and end of the event, or the single point
+//! in time it occurred at for "instant" events.
+//!
+//!
+//! ## Event Filtering
+//!
+//! Event generation can be filtered by event kind. Recording all possible
+//! events generates a lot of data, much of which is not needed for most kinds
+//! of analysis. So, in order to keep overhead as low as possible for a given
+//! use case, the `SelfProfiler` will only record the kinds of events that
+//! pass the filter specified as a command line argument to the compiler.
+//!
+//!
+//! ## `event_id` Assignment
+//!
+//! As far as `measureme` is concerned, `event_id`s are just strings. However,
+//! it would incur too much overhead to generate and persist each `event_id`
+//! string at the point where the event is recorded. In order to make this more
+//! efficient `measureme` has two features:
+//!
+//! - Strings can share their content, so that re-occurring parts don't have to
+//! be copied over and over again. One allocates a string in `measureme` and
+//! gets back a `StringId`. This `StringId` is then used to refer to that
+//! string. `measureme` strings are actually DAGs of string components so that
+//! arbitrary sharing of substrings can be done efficiently. This is useful
+//! because `event_id`s contain lots of redundant text like query names or
+//! def-path components.
+//!
+//! - `StringId`s can be "virtual" which means that the client picks a numeric
+//! ID according to some application-specific scheme and can later make that
+//! ID be mapped to an actual string. This is used to cheaply generate
+//! `event_id`s while the events actually occur, causing little timing
+//! distortion, and then later map those `StringId`s, in bulk, to actual
+//! `event_id` strings. This way the largest part of the tracing overhead is
+//! localized to one contiguous chunk of time.
+//!
+//! How are these `event_id`s generated in the compiler? For things that occur
+//! infrequently (e.g. "generic activities"), we just allocate the string the
+//! first time it is used and then keep the `StringId` in a hash table. This
+//! is implemented in `SelfProfiler::get_or_alloc_cached_string()`.
+//!
+//! For queries it gets more interesting: First we need a unique numeric ID for
+//! each query invocation (the `QueryInvocationId`). This ID is used as the
+//! virtual `StringId` we use as `event_id` for a given event. This ID has to
+//! be available both when the query is executed and later, together with the
+//! query key, when we allocate the actual `event_id` strings in bulk.
+//!
+//! We could make the compiler generate and keep track of such an ID for each
+//! query invocation but luckily we already have something that fits all the
+//! the requirements: the query's `DepNodeIndex`. So we use the numeric value
+//! of the `DepNodeIndex` as `event_id` when recording the event and then,
+//! just before the query context is dropped, we walk the entire query cache
+//! (which stores the `DepNodeIndex` along with the query key for each
+//! invocation) and allocate the corresponding strings together with a mapping
+//! for `DepNodeIndex as StringId`.
+//!
+//! [mm]: https://github.com/rust-lang/measureme/
+
+use crate::fx::FxHashMap;
+
use std::error::Error;
use std::fs;
-use std::mem::{self, Discriminant};
use std::path::Path;
use std::process;
use std::sync::Arc;
use std::thread::ThreadId;
+use std::time::{Duration, Instant};
use std::u32;
-use measureme::{StringId};
+use measureme::{EventId, EventIdBuilder, SerializableString, StringId};
+use parking_lot::RwLock;
/// MmapSerializatioSink is faster on macOS and Linux
/// but FileSerializationSink is faster on Windows
type Profiler = measureme::Profiler<SerializationSink>;
-pub trait QueryName: Sized + Copy {
- fn discriminant(self) -> Discriminant<Self>;
- fn as_str(self) -> &'static str;
-}
-
#[derive(Clone, Copy, Debug, PartialEq, Eq, Ord, PartialOrd)]
pub enum ProfileCategory {
Parsing,
const QUERY_BLOCKED = 1 << 3;
const INCR_CACHE_LOADS = 1 << 4;
+ const QUERY_KEYS = 1 << 5;
+
const DEFAULT = Self::GENERIC_ACTIVITIES.bits |
Self::QUERY_PROVIDERS.bits |
Self::QUERY_BLOCKED.bits |
}
}
+// keep this in sync with the `-Z self-profile-events` help message in librustc_session/options.rs
const EVENT_FILTERS_BY_NAME: &[(&str, EventFilter)] = &[
("none", EventFilter::NONE),
("all", EventFilter::ALL),
+ ("default", EventFilter::DEFAULT),
("generic-activity", EventFilter::GENERIC_ACTIVITIES),
("query-provider", EventFilter::QUERY_PROVIDERS),
("query-cache-hit", EventFilter::QUERY_CACHE_HITS),
- ("query-blocked" , EventFilter::QUERY_BLOCKED),
+ ("query-blocked", EventFilter::QUERY_BLOCKED),
("incr-cache-load", EventFilter::INCR_CACHE_LOADS),
+ ("query-keys", EventFilter::QUERY_KEYS),
];
fn thread_id_to_u32(tid: ThreadId) -> u32 {
- unsafe { mem::transmute::<ThreadId, u64>(tid) as u32 }
+ unsafe { std::mem::transmute::<ThreadId, u64>(tid) as u32 }
}
+/// Something that uniquely identifies a query invocation.
+pub struct QueryInvocationId(pub u32);
/// A reference to the SelfProfiler. It can be cloned and sent across thread
/// boundaries at will.
// cost anything and allows for filtering with checking if the profiler is
// actually enabled.
event_filter_mask: EventFilter,
+
+ // Print verbose generic activities to stdout
+ print_verbose_generic_activities: bool,
+
+ // Print extra verbose generic activities to stdout
+ print_extra_verbose_generic_activities: bool,
}
impl SelfProfilerRef {
-
- pub fn new(profiler: Option<Arc<SelfProfiler>>) -> SelfProfilerRef {
+ pub fn new(
+ profiler: Option<Arc<SelfProfiler>>,
+ print_verbose_generic_activities: bool,
+ print_extra_verbose_generic_activities: bool,
+ ) -> SelfProfilerRef {
// If there is no SelfProfiler then the filter mask is set to NONE,
// ensuring that nothing ever tries to actually access it.
- let event_filter_mask = profiler
- .as_ref()
- .map(|p| p.event_filter_mask)
- .unwrap_or(EventFilter::NONE);
+ let event_filter_mask =
+ profiler.as_ref().map(|p| p.event_filter_mask).unwrap_or(EventFilter::NONE);
SelfProfilerRef {
profiler,
event_filter_mask,
+ print_verbose_generic_activities,
+ print_extra_verbose_generic_activities,
}
}
// path.
#[inline(always)]
fn exec<F>(&self, event_filter: EventFilter, f: F) -> TimingGuard<'_>
- where F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>
+ where
+ F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>,
{
#[inline(never)]
fn cold_call<F>(profiler_ref: &SelfProfilerRef, f: F) -> TimingGuard<'_>
- where F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>
+ where
+ F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>,
{
let profiler = profiler_ref.profiler.as_ref().unwrap();
f(&**profiler)
}
}
+ /// Start profiling a verbose generic activity. Profiling continues until the
+ /// VerboseTimingGuard returned from this call is dropped. In addition to recording
+ /// a measureme event, "verbose" generic activities also print a timing entry to
+ /// stdout if the compiler is invoked with -Ztime or -Ztime-passes.
+ #[inline(always)]
+ pub fn verbose_generic_activity<'a>(
+ &'a self,
+ event_id: &'static str,
+ ) -> VerboseTimingGuard<'a> {
+ VerboseTimingGuard::start(
+ event_id,
+ self.print_verbose_generic_activities,
+ self.generic_activity(event_id),
+ )
+ }
+
+ /// Start profiling a extra verbose generic activity. Profiling continues until the
+ /// VerboseTimingGuard returned from this call is dropped. In addition to recording
+ /// a measureme event, "extra verbose" generic activities also print a timing entry to
+ /// stdout if the compiler is invoked with -Ztime-passes.
+ #[inline(always)]
+ pub fn extra_verbose_generic_activity<'a>(
+ &'a self,
+ event_id: &'a str,
+ ) -> VerboseTimingGuard<'a> {
+ // FIXME: This does not yet emit a measureme event
+ // because callers encode arguments into `event_id`.
+ VerboseTimingGuard::start(
+ event_id,
+ self.print_extra_verbose_generic_activities,
+ TimingGuard::none(),
+ )
+ }
+
/// Start profiling a generic activity. Profiling continues until the
/// TimingGuard returned from this call is dropped.
#[inline(always)]
- pub fn generic_activity(&self, event_id: &str) -> TimingGuard<'_> {
+ pub fn generic_activity(&self, event_id: &'static str) -> TimingGuard<'_> {
self.exec(EventFilter::GENERIC_ACTIVITIES, |profiler| {
- let event_id = profiler.profiler.alloc_string(event_id);
- TimingGuard::start(
- profiler,
- profiler.generic_activity_event_kind,
- event_id
- )
+ let event_id = profiler.get_or_alloc_cached_string(event_id);
+ let event_id = EventId::from_label(event_id);
+ TimingGuard::start(profiler, profiler.generic_activity_event_kind, event_id)
})
}
/// Start profiling a query provider. Profiling continues until the
/// TimingGuard returned from this call is dropped.
#[inline(always)]
- pub fn query_provider(&self, query_name: impl QueryName) -> TimingGuard<'_> {
+ pub fn query_provider(&self) -> TimingGuard<'_> {
self.exec(EventFilter::QUERY_PROVIDERS, |profiler| {
- let event_id = SelfProfiler::get_query_name_string_id(query_name);
- TimingGuard::start(profiler, profiler.query_event_kind, event_id)
+ TimingGuard::start(profiler, profiler.query_event_kind, EventId::INVALID)
})
}
/// Record a query in-memory cache hit.
#[inline(always)]
- pub fn query_cache_hit(&self, query_name: impl QueryName) {
+ pub fn query_cache_hit(&self, query_invocation_id: QueryInvocationId) {
self.instant_query_event(
|profiler| profiler.query_cache_hit_event_kind,
- query_name,
+ query_invocation_id,
EventFilter::QUERY_CACHE_HITS,
);
}
/// Profiling continues until the TimingGuard returned from this call is
/// dropped.
#[inline(always)]
- pub fn query_blocked(&self, query_name: impl QueryName) -> TimingGuard<'_> {
+ pub fn query_blocked(&self) -> TimingGuard<'_> {
self.exec(EventFilter::QUERY_BLOCKED, |profiler| {
- let event_id = SelfProfiler::get_query_name_string_id(query_name);
- TimingGuard::start(profiler, profiler.query_blocked_event_kind, event_id)
+ TimingGuard::start(profiler, profiler.query_blocked_event_kind, EventId::INVALID)
})
}
/// incremental compilation on-disk cache. Profiling continues until the
/// TimingGuard returned from this call is dropped.
#[inline(always)]
- pub fn incr_cache_loading(&self, query_name: impl QueryName) -> TimingGuard<'_> {
+ pub fn incr_cache_loading(&self) -> TimingGuard<'_> {
self.exec(EventFilter::INCR_CACHE_LOADS, |profiler| {
- let event_id = SelfProfiler::get_query_name_string_id(query_name);
TimingGuard::start(
profiler,
profiler.incremental_load_result_event_kind,
- event_id
+ EventId::INVALID,
)
})
}
fn instant_query_event(
&self,
event_kind: fn(&SelfProfiler) -> StringId,
- query_name: impl QueryName,
+ query_invocation_id: QueryInvocationId,
event_filter: EventFilter,
) {
drop(self.exec(event_filter, |profiler| {
- let event_id = SelfProfiler::get_query_name_string_id(query_name);
+ let event_id = StringId::new_virtual(query_invocation_id.0);
let thread_id = thread_id_to_u32(std::thread::current().id());
profiler.profiler.record_instant_event(
event_kind(profiler),
- event_id,
+ EventId::from_virtual(event_id),
thread_id,
);
}));
}
- pub fn register_queries(&self, f: impl FnOnce(&SelfProfiler)) {
+ pub fn with_profiler(&self, f: impl FnOnce(&SelfProfiler)) {
if let Some(profiler) = &self.profiler {
f(&profiler)
}
}
+
+ #[inline]
+ pub fn enabled(&self) -> bool {
+ self.profiler.is_some()
+ }
}
pub struct SelfProfiler {
profiler: Profiler,
event_filter_mask: EventFilter,
+
+ string_cache: RwLock<FxHashMap<&'static str, StringId>>,
+
query_event_kind: StringId,
generic_activity_event_kind: StringId,
incremental_load_result_event_kind: StringId,
pub fn new(
output_directory: &Path,
crate_name: Option<&str>,
- event_filters: &Option<Vec<String>>
+ event_filters: &Option<Vec<String>>,
) -> Result<SelfProfiler, Box<dyn Error>> {
fs::create_dir_all(output_directory)?;
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) {
+ if let Some(&(_, mask)) =
+ EVENT_FILTERS_BY_NAME.iter().find(|&(name, _)| name == item)
+ {
event_filter_mask |= mask;
} else {
unknown_events.push(item.clone());
unknown_events.sort();
unknown_events.dedup();
- warn!("Unknown self-profiler events specified: {}. Available options are: {}.",
+ 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(", "));
+ 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,
+ string_cache: RwLock::new(FxHashMap::default()),
query_event_kind,
generic_activity_event_kind,
incremental_load_result_event_kind,
})
}
- fn get_query_name_string_id(query_name: impl QueryName) -> StringId {
- let discriminant = unsafe {
- mem::transmute::<Discriminant<_>, u64>(query_name.discriminant())
- };
+ /// Allocates a new string in the profiling data. Does not do any caching
+ /// or deduplication.
+ pub fn alloc_string<STR: SerializableString + ?Sized>(&self, s: &STR) -> StringId {
+ self.profiler.alloc_string(s)
+ }
+
+ /// Gets a `StringId` for the given string. This method makes sure that
+ /// any strings going through it will only be allocated once in the
+ /// profiling data.
+ pub fn get_or_alloc_cached_string(&self, s: &'static str) -> StringId {
+ // Only acquire a read-lock first since we assume that the string is
+ // already present in the common case.
+ {
+ let string_cache = self.string_cache.read();
+
+ if let Some(&id) = string_cache.get(s) {
+ return id;
+ }
+ }
+
+ let mut string_cache = self.string_cache.write();
+ // Check if the string has already been added in the small time window
+ // between dropping the read lock and acquiring the write lock.
+ *string_cache.entry(s).or_insert_with(|| self.profiler.alloc_string(s))
+ }
+
+ pub fn map_query_invocation_id_to_string(&self, from: QueryInvocationId, to: StringId) {
+ let from = StringId::new_virtual(from.0);
+ self.profiler.map_virtual_to_concrete_string(from, to);
+ }
+
+ pub fn bulk_map_query_invocation_id_to_single_string<I>(&self, from: I, to: StringId)
+ where
+ I: Iterator<Item = QueryInvocationId> + ExactSizeIterator,
+ {
+ let from = from.map(|qid| StringId::new_virtual(qid.0));
+ self.profiler.bulk_map_virtual_to_single_concrete_string(from, to);
+ }
- StringId::reserved(discriminant as u32)
+ pub fn query_key_recording_enabled(&self) -> bool {
+ self.event_filter_mask.contains(EventFilter::QUERY_KEYS)
}
- pub fn register_query_name(&self, query_name: impl QueryName) {
- let id = SelfProfiler::get_query_name_string_id(query_name);
- self.profiler.alloc_string_with_reserved_id(id, query_name.as_str());
+ pub fn event_id_builder(&self) -> EventIdBuilder<'_, SerializationSink> {
+ EventIdBuilder::new(&self.profiler)
}
}
pub fn start(
profiler: &'a SelfProfiler,
event_kind: StringId,
- event_id: StringId,
+ event_id: EventId,
) -> TimingGuard<'a> {
let thread_id = thread_id_to_u32(std::thread::current().id());
let raw_profiler = &profiler.profiler;
- let timing_guard = raw_profiler.start_recording_interval_event(event_kind,
- event_id,
- thread_id);
+ let timing_guard =
+ raw_profiler.start_recording_interval_event(event_kind, event_id, thread_id);
TimingGuard(Some(timing_guard))
}
+ #[inline]
+ pub fn finish_with_query_invocation_id(self, query_invocation_id: QueryInvocationId) {
+ if let Some(guard) = self.0 {
+ let event_id = StringId::new_virtual(query_invocation_id.0);
+ let event_id = EventId::from_virtual(event_id);
+ guard.finish_with_override_event_id(event_id);
+ }
+ }
+
#[inline]
pub fn none() -> TimingGuard<'a> {
TimingGuard(None)
}
+
+ #[inline(always)]
+ pub fn run<R>(self, f: impl FnOnce() -> R) -> R {
+ let _timer = self;
+ f()
+ }
+}
+
+#[must_use]
+pub struct VerboseTimingGuard<'a> {
+ event_id: &'a str,
+ start: Option<Instant>,
+ _guard: TimingGuard<'a>,
+}
+
+impl<'a> VerboseTimingGuard<'a> {
+ pub fn start(event_id: &'a str, verbose: bool, _guard: TimingGuard<'a>) -> Self {
+ VerboseTimingGuard {
+ event_id,
+ _guard,
+ start: if unlikely!(verbose) { Some(Instant::now()) } else { None },
+ }
+ }
+
+ #[inline(always)]
+ pub fn run<R>(self, f: impl FnOnce() -> R) -> R {
+ let _timer = self;
+ f()
+ }
+}
+
+impl Drop for VerboseTimingGuard<'_> {
+ fn drop(&mut self) {
+ self.start.map(|start| print_time_passes_entry(true, self.event_id, start.elapsed()));
+ }
+}
+
+pub fn print_time_passes_entry(do_it: bool, what: &str, dur: Duration) {
+ if !do_it {
+ return;
+ }
+
+ let mem_string = match get_resident() {
+ Some(n) => {
+ let mb = n as f64 / 1_000_000.0;
+ format!("; rss: {}MB", mb.round() as usize)
+ }
+ None => String::new(),
+ };
+ println!("time: {}{}\t{}", duration_to_secs_str(dur), mem_string, what);
+}
+
+// Hack up our own formatting for the duration to make it easier for scripts
+// to parse (always use the same number of decimal places and the same unit).
+pub fn duration_to_secs_str(dur: std::time::Duration) -> String {
+ const NANOS_PER_SEC: f64 = 1_000_000_000.0;
+ let secs = dur.as_secs() as f64 + dur.subsec_nanos() as f64 / NANOS_PER_SEC;
+
+ format!("{:.3}", secs)
+}
+
+// Memory reporting
+#[cfg(unix)]
+fn get_resident() -> Option<usize> {
+ let field = 1;
+ let contents = fs::read("/proc/self/statm").ok()?;
+ let contents = String::from_utf8(contents).ok()?;
+ let s = contents.split_whitespace().nth(field)?;
+ let npages = s.parse::<usize>().ok()?;
+ Some(npages * 4096)
+}
+
+#[cfg(windows)]
+fn get_resident() -> Option<usize> {
+ use std::mem::{self, MaybeUninit};
+ use winapi::shared::minwindef::DWORD;
+ use winapi::um::processthreadsapi::GetCurrentProcess;
+ use winapi::um::psapi::{GetProcessMemoryInfo, PROCESS_MEMORY_COUNTERS};
+
+ let mut pmc = MaybeUninit::<PROCESS_MEMORY_COUNTERS>::uninit();
+ match unsafe {
+ GetProcessMemoryInfo(GetCurrentProcess(), pmc.as_mut_ptr(), mem::size_of_val(&pmc) as DWORD)
+ } {
+ 0 => None,
+ _ => {
+ let pmc = unsafe { pmc.assume_init() };
+ Some(pmc.WorkingSetSize as usize)
+ }
+ }
}
projects / rust.git / blobdiff