Merge #7334

7334: Add back jemalloc support r=jonas-schievink a=jonas-schievink

jemalloc is useful due to its introspection API, which allows obtaining quick and accurate memory usage statistics without running into `mallinfo`'s limitations.

Co-authored-by: Jonas Schievink <[email protected]>

2 files changed, 8 insertions, 1 deletions

diff --git a/crates/profile/Cargo.toml b/crates/profile/Cargo.toml
index 9c7ce26be..f7231c2b8 100644
--- a/crates/profile/Cargo.toml
+++ b/crates/profile/Cargo.toml
@@ -14,12 +14,14 @@ once_cell = "1.3.1"
 cfg-if = "1"
 libc = "0.2.73"
 la-arena = { version = "0.2.0", path = "../../lib/arena" }
+jemalloc-ctl = { version = "0.3.3", optional = true }
 
 [target.'cfg(target_os = "linux")'.dependencies]
 perf-event = "0.4"
 
 [features]
 cpu_profiler = []
+jemalloc = ["jemalloc-ctl"]
 
 # Uncomment to enable for the whole crate graph
 # default = [ "cpu_profiler" ]
diff --git a/crates/profile/src/memory_usage.rs b/crates/profile/src/memory_usage.rs
index 83390212a..cb4e54447 100644
--- a/crates/profile/src/memory_usage.rs
+++ b/crates/profile/src/memory_usage.rs
@@ -24,7 +24,12 @@ impl std::ops::Sub for MemoryUsage {
 impl MemoryUsage {
     pub fn current() -> MemoryUsage {
         cfg_if! {
-            if #[cfg(all(target_os = "linux", target_env = "gnu"))] {
+            if #[cfg(all(feature = "jemalloc", not(target_env = "msvc")))] {
+                jemalloc_ctl::epoch::advance().unwrap();
+                MemoryUsage {
+                    allocated: Bytes(jemalloc_ctl::stats::allocated::read().unwrap() as isize),
+                }
+            } else if #[cfg(all(target_os = "linux", target_env = "gnu"))] {
                 // Note: This is incredibly slow.
                 let alloc = unsafe { libc::mallinfo() }.uordblks as isize;
                 MemoryUsage { allocated: Bytes(alloc) }