From 1988bc8d3782ce29fcd223b184fb78a141f5f4f8 Mon Sep 17 00:00:00 2001
From: Weihang Lo <me@weihanglo.tw>
Date: Sat, 26 Feb 2022 15:47:33 +0800
Subject: [PATCH 1/2] Use `available_parallelism` instead of num_cpus
`std::thread::available_parallelism` has been stabilized since 1.59.0.
Also, we don't want to block timing data output, so if parallelism
data is not available the table will display `ncpu=n/a` instead.
---
Cargo.toml | 1 -
src/cargo/core/compiler/build_config.rs | 6 +++++-
src/cargo/core/compiler/timings.rs | 6 +++++-
3 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/Cargo.toml b/Cargo.toml
index 9110ab5aba6..baa20a8c7b8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -43,7 +43,6 @@ libc = "0.2"
log = "0.4.6"
libgit2-sys = "0.12.24"
memchr = "2.1.3"
-num_cpus = "1.0"
opener = "0.5"
os_info = "3.0.7"
percent-encoding = "2.0"
diff --git a/src/cargo/core/compiler/build_config.rs b/src/cargo/core/compiler/build_config.rs
index e7964afe72b..54b2fd9b12c 100644
--- a/src/cargo/core/compiler/build_config.rs
+++ b/src/cargo/core/compiler/build_config.rs
@@ -6,6 +6,7 @@ use cargo_util::ProcessBuilder;
use serde::ser;
use std::cell::RefCell;
use std::path::PathBuf;
+use std::thread::available_parallelism;
/// Configuration information for a rustc build.
#[derive(Debug)]
@@ -70,7 +71,10 @@ impl BuildConfig {
its environment, ignoring the `-j` parameter",
)?;
}
- let jobs = jobs.or(cfg.jobs).unwrap_or(::num_cpus::get() as u32);
+ let jobs = match jobs.or(cfg.jobs) {
+ Some(j) => j,
+ None => available_parallelism()?.get() as u32,
+ };
if jobs == 0 {
anyhow::bail!("jobs may not be 0");
}
diff --git a/src/cargo/core/compiler/timings.rs b/src/cargo/core/compiler/timings.rs
index 77dcec94f6d..9242af9d83c 100644
--- a/src/cargo/core/compiler/timings.rs
+++ b/src/cargo/core/compiler/timings.rs
@@ -13,6 +13,7 @@ use anyhow::Context as _;
use cargo_util::paths;
use std::collections::HashMap;
use std::io::{BufWriter, Write};
+use std::thread::available_parallelism;
use std::time::{Duration, Instant, SystemTime};
pub struct Timings<'cfg> {
@@ -380,6 +381,9 @@ impl<'cfg> Timings<'cfg> {
};
let total_time = format!("{:.1}s{}", duration, time_human);
let max_concurrency = self.concurrency.iter().map(|c| c.active).max().unwrap();
+ let num_cpus = available_parallelism()
+ .map(|x| x.get().to_string())
+ .unwrap_or_else(|_| "n/a".into());
let max_rustc_concurrency = self
.concurrency
.iter()
@@ -442,7 +446,7 @@ impl<'cfg> Timings<'cfg> {
self.total_fresh + self.total_dirty,
max_concurrency,
bcx.build_config.jobs,
- num_cpus::get(),
+ num_cpus,
self.start_str,
total_time,
rustc_info,
From 4f706ae8d5877b09520e1ebc616165cac3c499e2 Mon Sep 17 00:00:00 2001
From: Weihang Lo <me@weihanglo.tw>
Date: Wed, 2 Mar 2022 19:41:31 +0800
Subject: [PATCH 2/2] Wrap an error context for determining the amount of
parallelism
---
src/cargo/core/compiler/build_config.rs | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/src/cargo/core/compiler/build_config.rs b/src/cargo/core/compiler/build_config.rs
index 54b2fd9b12c..31cd3e3da53 100644
--- a/src/cargo/core/compiler/build_config.rs
+++ b/src/cargo/core/compiler/build_config.rs
@@ -1,7 +1,7 @@
use crate::core::compiler::CompileKind;
use crate::util::interning::InternedString;
use crate::util::{CargoResult, Config, RustfixDiagnosticServer};
-use anyhow::bail;
+use anyhow::{bail, Context as _};
use cargo_util::ProcessBuilder;
use serde::ser;
use std::cell::RefCell;
@@ -73,7 +73,9 @@ impl BuildConfig {
}
let jobs = match jobs.or(cfg.jobs) {
Some(j) => j,
- None => available_parallelism()?.get() as u32,
+ None => available_parallelism()
+ .context("failed to determine the amount of parallelism available")?
+ .get() as u32,
};
if jobs == 0 {
anyhow::bail!("jobs may not be 0");