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Auto merge of #83152 - guswynn:jemallocator_part2, r=Mark-Simulacrum

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Use tikv-jemallocator in rustc/rustdoc in addition to jemalloc-sys when enabled.

In https://github.com/rust-lang/rust/pull/81782 it was mentioned that one reason rustc may benefit from minimalloc is it doesn't use the `sdallocx` api from jemalloc.

Currently, on unix, rust uses jemalloc by importing its symbols to use them with the default, System (libc) global allocator.
This PR switches its global alloc to `tikv-jemallocator`, which correctly uses sized deallocation (https://docs.rs/tikv-jemallocator/0.4.1/src/tikv_jemallocator/lib.rs.html#121-126). `tikv-jemallocator`, as far as I can tell, is a more up-to-date set of bindings to jemalloc than `jemallocator`

The perf results of this pr are in large part due to the version upgrade of jemalloc, but sized deallocation has a non-trivial improvement, particularly to rustdoc.

This pr also includes changes to bootstrap to correctly pass the jemalloc feature through to the rustdoc build
This commit is contained in:
bors 2021-04-05 21:14:27 +00:00
commit d322385321
7 changed files with 107 additions and 17 deletions
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10
compiler/rustc/Cargo.toml
View file

@ -11,12 +11,16 @@ rustc_driver = { path = "../rustc_driver" }
# crate is intended to be used by codegen backends, which may not be in-tree.
rustc_codegen_ssa = { path = "../rustc_codegen_ssa" }
[dependencies.jemalloc-sys]
version = '0.3.0'
[dependencies.tikv-jemalloc-sys]
version = '0.4.0'
optional = true
features = ['unprefixed_malloc_on_supported_platforms']
[dependencies.tikv-jemallocator]
version = '0.4.0'
optional = true
[features]
jemalloc = ['jemalloc-sys']
jemalloc = ['tikv-jemalloc-sys', 'tikv-jemallocator']
llvm = ['rustc_driver/llvm']
max_level_info = ['rustc_driver/max_level_info']

15
compiler/rustc/src/main.rs
View file

@ -1,3 +1,16 @@
// Configure jemalloc as the `global_allocator` when configured. This is
// so that we use the sized deallocation apis jemalloc provides
// (namely `sdallocx`).
//
// The symbol overrides documented below are also performed so that we can
// ensure that we use a consistent allocator across the rustc <-> llvm boundary
#[cfg(feature = "jemalloc")]
#[global_allocator]
static ALLOC: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
#[cfg(feature = "tikv-jemalloc-sys")]
use tikv_jemalloc_sys as jemalloc_sys;
fn main() {
// Pull in jemalloc when enabled.
//
@ -7,7 +20,7 @@ fn main() {
// dynamic libraries. That means to pull in jemalloc we actually need to
// reference allocation symbols one way or another (as this file is the only
// object code in the rustc executable).
#[cfg(feature = "jemalloc-sys")]
#[cfg(feature = "tikv-jemalloc-sys")]
{
use std::os::raw::{c_int, c_void};