From 1e7faef2204f02d79506559d298f61dc3dcd24b3 Mon Sep 17 00:00:00 2001
From: Eduard-Mihai Burtescu <edy.burt@gmail.com>
Date: Tue, 10 Sep 2019 13:43:54 +0300
Subject: [PATCH] rustc_mir: buffer -Zdump-mir output instead of pestering the
 kernel constantly.

---
 src/librustc_mir/util/pretty.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/librustc_mir/util/pretty.rs b/src/librustc_mir/util/pretty.rs
index ac2701971dfd5..c35c9e4da9f48 100644
--- a/src/librustc_mir/util/pretty.rs
+++ b/src/librustc_mir/util/pretty.rs
@@ -227,12 +227,12 @@ pub(crate) fn create_dump_file(
     pass_name: &str,
     disambiguator: &dyn Display,
     source: MirSource<'tcx>,
-) -> io::Result<fs::File> {
+) -> io::Result<io::BufWriter<fs::File>> {
     let file_path = dump_path(tcx, extension, pass_num, pass_name, disambiguator, source);
     if let Some(parent) = file_path.parent() {
         fs::create_dir_all(parent)?;
     }
-    fs::File::create(&file_path)
+    Ok(io::BufWriter::new(fs::File::create(&file_path)?))
 }
 
 /// Write out a human-readable textual representation for the given MIR.