Auto merge of #18227 - davidbarsky:davidbarsky/push-lmntvwvznyyx, r=davidbarsky

internal: add json `tracing` Layer for profiling startup

On `buck2/integrations/rust-project`, this results in the following being printed:

```json
{"name":"discover_command","elapsed_ms":18703}
{"name":"parallel_prime_caches","elapsed_ms":0}
{"name":"vfs_load","elapsed_ms":5895}
{"name":"vfs_load","elapsed_ms":547}
{"name":"parallel_prime_caches","elapsed_ms":23}
{"name":"parallel_prime_caches","elapsed_ms":84}
{"name":"parallel_prime_caches","elapsed_ms":5819}
```
This commit is contained in:
bors 2024-10-04 17:59:02 +00:00
commit 5982d9c420
8 changed files with 186 additions and 58 deletions

View file

@ -556,7 +556,7 @@ impl Module {
acc: &mut Vec<AnyDiagnostic>,
style_lints: bool,
) {
let _p = tracing::info_span!("Module::diagnostics", name = ?self.name(db)).entered();
let _p = tracing::info_span!("diagnostics", name = ?self.name(db)).entered();
let edition = db.crate_graph()[self.id.krate()].edition;
let def_map = self.id.def_map(db.upcast());
for diag in def_map.diagnostics() {

View file

@ -137,6 +137,7 @@ fn setup_logging(log_file_flag: Option<PathBuf>) -> anyhow::Result<()> {
filter: env::var("RA_LOG").ok().unwrap_or_else(|| "error".to_owned()),
chalk_filter: env::var("CHALK_DEBUG").ok(),
profile_filter: env::var("RA_PROFILE").ok(),
json_profile_filter: std::env::var("RA_PROFILE_JSON").ok(),
}
.init()?;

View file

@ -34,6 +34,7 @@ mod handlers {
pub mod tracing {
pub mod config;
pub mod json;
pub use config::Config;
pub mod hprof;
}

View file

@ -1,17 +1,20 @@
//! Simple logger that logs either to stderr or to a file, using `tracing_subscriber`
//! filter syntax and `tracing_appender` for non blocking output.
use std::io;
use std::io::{self};
use anyhow::Context;
use tracing::level_filters::LevelFilter;
use tracing_subscriber::{
filter::Targets, fmt::MakeWriter, layer::SubscriberExt, util::SubscriberInitExt, Layer,
Registry,
filter::{filter_fn, Targets},
fmt::MakeWriter,
layer::SubscriberExt,
Layer, Registry,
};
use tracing_tree::HierarchicalLayer;
use crate::tracing::hprof;
use crate::tracing::json;
#[derive(Debug)]
pub struct Config<T> {
@ -34,6 +37,12 @@ pub struct Config<T> {
/// env RA_PROFILE=*@3>10 // dump everything, up to depth 3, if it takes more than 10
/// ```
pub profile_filter: Option<String>,
/// Filtering syntax, set in a shell:
/// ```
/// env RA_PROFILE_JSON=foo|bar|baz
/// ```
pub json_profile_filter: Option<String>,
}
impl<T> Config<T>
@ -41,7 +50,7 @@ where
T: for<'writer> MakeWriter<'writer> + Send + Sync + 'static,
{
pub fn init(self) -> anyhow::Result<()> {
let filter: Targets = self
let targets_filter: Targets = self
.filter
.parse()
.with_context(|| format!("invalid log filter: `{}`", self.filter))?;
@ -52,30 +61,58 @@ where
.with_target(false)
.with_ansi(false)
.with_writer(writer)
.with_filter(filter);
.with_filter(targets_filter);
let mut chalk_layer = None;
if let Some(chalk_filter) = self.chalk_filter {
let level: LevelFilter =
chalk_filter.parse().with_context(|| "invalid chalk log filter")?;
let chalk_layer = match self.chalk_filter {
Some(chalk_filter) => {
let level: LevelFilter =
chalk_filter.parse().with_context(|| "invalid chalk log filter")?;
let chalk_filter = Targets::new()
.with_target("chalk_solve", level)
.with_target("chalk_ir", level)
.with_target("chalk_recursive", level);
chalk_layer = Some(
let chalk_filter = Targets::new()
.with_target("chalk_solve", level)
.with_target("chalk_ir", level)
.with_target("chalk_recursive", level);
// TODO: remove `.with_filter(LevelFilter::OFF)` on the `None` branch.
HierarchicalLayer::default()
.with_indent_lines(true)
.with_ansi(false)
.with_indent_amount(2)
.with_writer(io::stderr)
.with_filter(chalk_filter),
);
.with_filter(chalk_filter)
.boxed()
}
None => None::<HierarchicalLayer>.with_filter(LevelFilter::OFF).boxed(),
};
let profiler_layer = self.profile_filter.map(|spec| hprof::layer(&spec));
// TODO: remove `.with_filter(LevelFilter::OFF)` on the `None` branch.
let profiler_layer = match self.profile_filter {
Some(spec) => Some(hprof::SpanTree::new(&spec)).with_filter(LevelFilter::INFO),
None => None.with_filter(LevelFilter::OFF),
};
Registry::default().with(ra_fmt_layer).with(chalk_layer).with(profiler_layer).try_init()?;
let json_profiler_layer = match self.json_profile_filter {
Some(spec) => {
let filter = json::JsonFilter::from_spec(&spec);
let filter = filter_fn(move |metadata| {
let allowed = match &filter.allowed_names {
Some(names) => names.contains(metadata.name()),
None => true,
};
allowed && metadata.is_span()
});
Some(json::TimingLayer::new(std::io::stderr).with_filter(filter))
}
None => None,
};
let subscriber = Registry::default()
.with(ra_fmt_layer)
.with(json_profiler_layer)
.with(profiler_layer)
.with(chalk_layer);
tracing::subscriber::set_global_default(subscriber)?;
Ok(())
}

View file

@ -33,6 +33,7 @@
use std::{
fmt::Write,
marker::PhantomData,
mem,
time::{Duration, Instant},
};
@ -50,53 +51,42 @@ use tracing_subscriber::{
Layer, Registry,
};
use crate::tracing::hprof;
pub fn init(spec: &str) -> tracing::subscriber::DefaultGuard {
let subscriber = Registry::default().with(layer(spec));
let subscriber = Registry::default().with(SpanTree::new(spec));
tracing::subscriber::set_default(subscriber)
}
pub fn layer<S>(spec: &str) -> impl Layer<S>
#[derive(Debug)]
pub(crate) struct SpanTree<S> {
aggregate: bool,
write_filter: WriteFilter,
_inner: PhantomData<fn(S)>,
}
impl<S> SpanTree<S>
where
S: Subscriber + for<'span> tracing_subscriber::registry::LookupSpan<'span>,
{
let (write_filter, allowed_names) = WriteFilter::from_spec(spec);
pub(crate) fn new(spec: &str) -> impl Layer<S> {
let (write_filter, allowed_names) = WriteFilter::from_spec(spec);
// this filter the first pass for `tracing`: these are all the "profiling" spans, but things like
// span depth or duration are not filtered here: that only occurs at write time.
let profile_filter = filter::filter_fn(move |metadata| {
let allowed = match &allowed_names {
Some(names) => names.contains(metadata.name()),
None => true,
};
// this filter the first pass for `tracing`: these are all the "profiling" spans, but things like
// span depth or duration are not filtered here: that only occurs at write time.
let profile_filter = filter::filter_fn(move |metadata| {
let allowed = match &allowed_names {
Some(names) => names.contains(metadata.name()),
None => true,
};
allowed
&& metadata.is_span()
&& metadata.level() >= &Level::INFO
&& !metadata.target().starts_with("salsa")
&& metadata.name() != "compute_exhaustiveness_and_usefulness"
&& !metadata.target().starts_with("chalk")
});
allowed
&& metadata.is_span()
&& metadata.level() >= &Level::INFO
&& !metadata.target().starts_with("salsa")
&& metadata.name() != "compute_exhaustiveness_and_usefulness"
&& !metadata.target().starts_with("chalk")
});
hprof::SpanTree::default().aggregate(true).spec_filter(write_filter).with_filter(profile_filter)
}
#[derive(Default, Debug)]
pub(crate) struct SpanTree {
aggregate: bool,
write_filter: WriteFilter,
}
impl SpanTree {
/// Merge identical sibling spans together.
pub(crate) fn aggregate(self, yes: bool) -> SpanTree {
SpanTree { aggregate: yes, ..self }
}
/// Add a write-time filter for span duration or tree depth.
pub(crate) fn spec_filter(self, write_filter: WriteFilter) -> SpanTree {
SpanTree { write_filter, ..self }
Self { aggregate: true, write_filter, _inner: PhantomData }.with_filter(profile_filter)
}
}
@ -136,7 +126,7 @@ impl<'a> Visit for DataVisitor<'a> {
}
}
impl<S> Layer<S> for SpanTree
impl<S> Layer<S> for SpanTree<S>
where
S: Subscriber + for<'span> LookupSpan<'span>,
{

View file

@ -0,0 +1,90 @@
//! A [tracing_subscriber::layer::Layer] that exports new-line delinated JSON.
//!
//! Usage:
//!
//! ```rust
//! let layer = json::TimingLayer::new(std::io::stderr);
//! Registry::default().with(layer).init();
//! ```
use std::{io::Write as _, marker::PhantomData, time::Instant};
use ide_db::FxHashSet;
use tracing::{
span::{Attributes, Id},
Event, Subscriber,
};
use tracing_subscriber::{fmt::MakeWriter, layer::Context, registry::LookupSpan, Layer};
struct JsonData {
name: &'static str,
start: std::time::Instant,
}
impl JsonData {
fn new(name: &'static str) -> Self {
Self { name, start: Instant::now() }
}
}
#[derive(Debug)]
pub(crate) struct TimingLayer<S, W> {
writer: W,
_inner: PhantomData<fn(S)>,
}
impl<S, W> TimingLayer<S, W> {
pub(crate) fn new(writer: W) -> Self {
Self { writer, _inner: PhantomData }
}
}
impl<S, W> Layer<S> for TimingLayer<S, W>
where
S: Subscriber + for<'span> LookupSpan<'span>,
W: for<'writer> MakeWriter<'writer> + Send + Sync + 'static,
{
fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>) {
let span = ctx.span(id).unwrap();
let data = JsonData::new(attrs.metadata().name());
span.extensions_mut().insert(data);
}
fn on_event(&self, _event: &Event<'_>, _ctx: Context<'_, S>) {}
fn on_close(&self, id: Id, ctx: Context<'_, S>) {
#[derive(serde::Serialize)]
struct JsonDataInner {
name: &'static str,
elapsed_ms: u128,
}
let span = ctx.span(&id).unwrap();
let Some(data) = span.extensions_mut().remove::<JsonData>() else {
return;
};
let data = JsonDataInner { name: data.name, elapsed_ms: data.start.elapsed().as_millis() };
let mut out = serde_json::to_string(&data).expect("Unable to serialize data");
out.push('\n');
self.writer.make_writer().write_all(out.as_bytes()).expect("Unable to write data");
}
}
#[derive(Default, Clone, Debug)]
pub(crate) struct JsonFilter {
pub(crate) allowed_names: Option<FxHashSet<String>>,
}
impl JsonFilter {
pub(crate) fn from_spec(spec: &str) -> Self {
let allowed_names = if spec == "*" {
None
} else {
Some(FxHashSet::from_iter(spec.split('|').map(String::from)))
};
Self { allowed_names }
}
}

View file

@ -103,6 +103,7 @@ impl Project<'_> {
filter: std::env::var("RA_LOG").ok().unwrap_or_else(|| "error".to_owned()),
chalk_filter: std::env::var("CHALK_DEBUG").ok(),
profile_filter: std::env::var("RA_PROFILE").ok(),
json_profile_filter: std::env::var("RA_PROFILE_JSON").ok(),
};
});

View file

@ -178,7 +178,15 @@ RA_PROFILE=foo|bar|baz // enabled only selected entries
RA_PROFILE=*@3>10 // dump everything, up to depth 3, if it takes more than 10 ms
```
In particular, I have `export RA_PROFILE='*>10'` in my shell profile.
Some rust-analyzer contributors have `export RA_PROFILE='*>10'` in my shell profile.
For machine-readable JSON output, we have the `RA_PROFILE_JSON` env variable. We support
filtering only by span name:
```
RA_PROFILE=* // dump everything
RA_PROFILE_JSON="vfs_load|parallel_prime_caches|discover_command" // dump selected spans
```
We also have a "counting" profiler which counts number of instances of popular structs.
It is enabled by `RA_COUNT=1`.