3 files changed, 22 insertions, 13 deletions

diff --git a/Cargo.lock b/Cargo.lock
index cf4de8bbe..4a8271f09 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -216,12 +216,12 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-channel"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cced8691919c02aac3cb0a1bc2e9b73d89e832bf9a06fc579d4e71b68a2da061"
+checksum = "09ee0cc8804d5393478d743b035099520087a5186f3b93fa58cec08fa62407b6"
 dependencies = [
+ "cfg-if",
  "crossbeam-utils",
- "maybe-uninit",
 ]
 
 [[package]]
@@ -1198,8 +1198,10 @@ name = "ra_prof"
 version = "0.1.0"
 dependencies = [
  "backtrace",
+ "cfg-if",
  "jemalloc-ctl",
  "jemallocator",
+ "libc",
  "mimalloc",
  "once_cell",
  "ra_arena",
diff --git a/crates/ra_prof/Cargo.toml b/crates/ra_prof/Cargo.toml
index b3d52985a..2e60858f1 100644
--- a/crates/ra_prof/Cargo.toml
+++ b/crates/ra_prof/Cargo.toml
@@ -14,6 +14,8 @@ ra_arena = { path = "../ra_arena" }
 once_cell = "1.3.1"
 backtrace = { version = "0.3.44", optional = true }
 mimalloc = { version = "0.1.19", default-features = false, optional = true }
+cfg-if = "0.1.10"
+libc = "0.2.73"
 
 [target.'cfg(not(target_env = "msvc"))'.dependencies]
 jemallocator = { version = "0.3.2", optional = true }
diff --git a/crates/ra_prof/src/memory_usage.rs b/crates/ra_prof/src/memory_usage.rs
index 9768f656c..b1858b06f 100644
--- a/crates/ra_prof/src/memory_usage.rs
+++ b/crates/ra_prof/src/memory_usage.rs
@@ -1,5 +1,6 @@
 //! FIXME: write short doc here
 
+use cfg_if::cfg_if;
 use std::fmt;
 
 pub struct MemoryUsage {
@@ -8,19 +9,23 @@ pub struct MemoryUsage {
 }
 
 impl MemoryUsage {
-    #[cfg(all(feature = "jemalloc", not(target_env = "msvc")))]
     pub fn current() -> MemoryUsage {
-        jemalloc_ctl::epoch::advance().unwrap();
-        MemoryUsage {
-            allocated: Bytes(jemalloc_ctl::stats::allocated::read().unwrap()),
-            resident: Bytes(jemalloc_ctl::stats::resident::read().unwrap()),
+        cfg_if! {
+            if #[cfg(all(feature = "jemalloc", not(target_env = "msvc")))] {
+                jemalloc_ctl::epoch::advance().unwrap();
+                MemoryUsage {
+                    allocated: Bytes(jemalloc_ctl::stats::allocated::read().unwrap()),
+                    resident: Bytes(jemalloc_ctl::stats::resident::read().unwrap()),
+                }
+            } else if #[cfg(target_os = "linux")] {
+                // Note: This is incredibly slow.
+                let alloc = unsafe { libc::mallinfo() }.uordblks as u32 as usize;
+                MemoryUsage { allocated: Bytes(alloc), resident: Bytes(0) }
+            } else {
+                MemoryUsage { allocated: Bytes(0), resident: Bytes(0) }
+            }
         }
     }
-
-    #[cfg(any(not(feature = "jemalloc"), target_env = "msvc"))]
-    pub fn current() -> MemoryUsage {
-        MemoryUsage { allocated: Bytes(0), resident: Bytes(0) }
-    }
 }
 
 impl fmt::Display for MemoryUsage {