diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 0bb0208e2a1b4..d107762385129 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -44,7 +44,7 @@ use std::cmp::{self, Ordering};
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::ops::Deref;
-use rustc_data_structures::sync::Lrc;
+use rustc_data_structures::sync::{self, Lrc, ParallelIterator, par_iter};
 use std::slice;
 use std::vec::IntoIter;
 use std::mem;
@@ -2434,6 +2434,12 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 .map(move |&body_id| self.hir.body_owner_def_id(body_id))
     }
 
+    pub fn par_body_owners<F: Fn(DefId) + sync::Sync + sync::Send>(self, f: F) {
+        par_iter(&self.hir.krate().body_ids).for_each(|&body_id| {
+            f(self.hir.body_owner_def_id(body_id))
+        });
+    }
+
     pub fn expr_span(self, id: NodeId) -> Span {
         match self.hir.find(id) {
             Some(hir_map::NodeExpr(e)) => {
diff --git a/src/librustc_borrowck/borrowck/mod.rs b/src/librustc_borrowck/borrowck/mod.rs
index e063880028fc9..2b817d4da30d9 100644
--- a/src/librustc_borrowck/borrowck/mod.rs
+++ b/src/librustc_borrowck/borrowck/mod.rs
@@ -67,9 +67,9 @@ pub struct LoanDataFlowOperator;
 pub type LoanDataFlow<'a, 'tcx> = DataFlowContext<'a, 'tcx, LoanDataFlowOperator>;
 
 pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
-    for body_owner_def_id in tcx.body_owners() {
+    tcx.par_body_owners(|body_owner_def_id| {
         tcx.borrowck(body_owner_def_id);
-    }
+    });
 }
 
 pub fn provide(providers: &mut Providers) {
diff --git a/src/librustc_borrowck/lib.rs b/src/librustc_borrowck/lib.rs
index 52a357e1a1d31..a5a20af0e4e4a 100644
--- a/src/librustc_borrowck/lib.rs
+++ b/src/librustc_borrowck/lib.rs
@@ -17,6 +17,8 @@
 #![feature(from_ref)]
 #![feature(quote)]
 
+#![recursion_limit="256"]
+
 #[macro_use] extern crate log;
 extern crate syntax;
 extern crate syntax_pos;
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 8dcbda917b243..ea7d3425f90b1 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -1264,11 +1264,9 @@ where
 
             time(sess, "borrow checking", || borrowck::check_crate(tcx));
 
-            time(sess, "MIR borrow checking", || {
-                for def_id in tcx.body_owners() {
-                    tcx.mir_borrowck(def_id);
-                }
-            });
+            time(sess,
+                 "MIR borrow checking",
+                 || tcx.par_body_owners(|def_id| { tcx.mir_borrowck(def_id); }));
 
             time(sess, "dumping chalk-like clauses", || {
                 rustc_traits::lowering::dump_program_clauses(tcx);
diff --git a/src/librustc_incremental/lib.rs b/src/librustc_incremental/lib.rs
index ababce69e3170..3839c133a6eb2 100644
--- a/src/librustc_incremental/lib.rs
+++ b/src/librustc_incremental/lib.rs
@@ -17,6 +17,8 @@
 #![feature(fs_read_write)]
 #![feature(specialization)]
 
+#![recursion_limit="256"]
+
 extern crate graphviz;
 #[macro_use] extern crate rustc;
 extern crate rustc_data_structures;
diff --git a/src/librustc_incremental/persist/save.rs b/src/librustc_incremental/persist/save.rs
index be725b1793321..dcef0c662c3a1 100644
--- a/src/librustc_incremental/persist/save.rs
+++ b/src/librustc_incremental/persist/save.rs
@@ -13,6 +13,7 @@ use rustc::session::Session;
 use rustc::ty::TyCtxt;
 use rustc::util::common::time;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sync::join;
 use rustc_serialize::Encodable as RustcEncodable;
 use rustc_serialize::opaque::Encoder;
 use std::io::{self, Cursor};
@@ -33,23 +34,28 @@ pub fn save_dep_graph<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
             return;
         }
 
-        time(sess, "persist query result cache", || {
-            save_in(sess,
-                    query_cache_path(sess),
-                    |e| encode_query_cache(tcx, e));
-        });
+        let query_cache_path = query_cache_path(sess);
+        let dep_graph_path = dep_graph_path(sess);
 
-        if tcx.sess.opts.debugging_opts.incremental_queries {
+        join(move || {
+            if tcx.sess.opts.debugging_opts.incremental_queries {
+                time(sess, "persist query result cache", || {
+                    save_in(sess,
+                            query_cache_path,
+                            |e| encode_query_cache(tcx, e));
+                });
+            }
+        }, || {
             time(sess, "persist dep-graph", || {
                 save_in(sess,
-                        dep_graph_path(sess),
+                        dep_graph_path,
                         |e| {
                             time(sess, "encode dep-graph", || {
                                 encode_dep_graph(tcx, e)
                             })
                         });
             });
-        }
+        });
 
         dirty_clean::check_dirty_clean_annotations(tcx);
     })
diff --git a/src/librustc_mir/lib.rs b/src/librustc_mir/lib.rs
index 34eb444fdc0cb..6ba5d02243cde 100644
--- a/src/librustc_mir/lib.rs
+++ b/src/librustc_mir/lib.rs
@@ -34,7 +34,10 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(specialization)]
 #![feature(try_trait)]
 
+#![recursion_limit="256"]
+
 extern crate arena;
+
 #[macro_use]
 extern crate bitflags;
 #[macro_use] extern crate log;
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index a8a50e14c6822..f509a54d9c725 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -207,10 +207,12 @@ use rustc::mir::interpret::{Scalar, GlobalId, AllocType};
 
 use monomorphize::{self, Instance};
 use rustc::util::nodemap::{FxHashSet, FxHashMap, DefIdMap};
+use rustc::util::common::time;
 
 use monomorphize::item::{MonoItemExt, DefPathBasedNames, InstantiationMode};
 
 use rustc_data_structures::bitvec::BitVector;
+use rustc_data_structures::sync::{ParallelIterator, par_iter, Lock};
 
 #[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
 pub enum MonoItemCollectionMode {
@@ -298,22 +300,26 @@ pub fn collect_crate_mono_items<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                           mode: MonoItemCollectionMode)
                                           -> (FxHashSet<MonoItem<'tcx>>,
                                                      InliningMap<'tcx>) {
-    let roots = collect_roots(tcx, mode);
+    let roots = time(tcx.sess, "collecting roots", || {
+        collect_roots(tcx, mode)
+    });
 
     debug!("Building mono item graph, beginning at roots");
-    let mut visited = FxHashSet();
-    let mut recursion_depths = DefIdMap();
-    let mut inlining_map = InliningMap::new();
-
-    for root in roots {
-        collect_items_rec(tcx,
-                          root,
-                          &mut visited,
-                          &mut recursion_depths,
-                          &mut inlining_map);
-    }
+    let visited = Lock::new(FxHashSet());
+    let inlining_map = Lock::new(InliningMap::new());
+
+    time(tcx.sess, "collecting mono items", || {
+        par_iter(roots).for_each(|root| {
+            let mut recursion_depths = DefIdMap();
+            collect_items_rec(tcx,
+                              root,
+                              &visited,
+                              &mut recursion_depths,
+                              &inlining_map);
+        });
+    });
 
-    (visited, inlining_map)
+    (visited.into_inner(), inlining_map.into_inner())
 }
 
 // Find all non-generic items by walking the HIR. These items serve as roots to
@@ -354,10 +360,10 @@ fn collect_roots<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 // Collect all monomorphized items reachable from `starting_point`
 fn collect_items_rec<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                    starting_point: MonoItem<'tcx>,
-                                   visited: &mut FxHashSet<MonoItem<'tcx>>,
+                                   visited: &Lock<FxHashSet<MonoItem<'tcx>>>,
                                    recursion_depths: &mut DefIdMap<usize>,
-                                   inlining_map: &mut InliningMap<'tcx>) {
-    if !visited.insert(starting_point.clone()) {
+                                   inlining_map: &Lock<InliningMap<'tcx>>) {
+    if !visited.lock().insert(starting_point.clone()) {
         // We've been here already, no need to search again.
         return;
     }
@@ -425,7 +431,7 @@ fn collect_items_rec<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 fn record_accesses<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                              caller: MonoItem<'tcx>,
                              callees: &[MonoItem<'tcx>],
-                             inlining_map: &mut InliningMap<'tcx>) {
+                             inlining_map: &Lock<InliningMap<'tcx>>) {
     let is_inlining_candidate = |mono_item: &MonoItem<'tcx>| {
         mono_item.instantiation_mode(tcx) == InstantiationMode::LocalCopy
     };
@@ -435,7 +441,7 @@ fn record_accesses<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                              (*mono_item, is_inlining_candidate(mono_item))
                           });
 
-    inlining_map.record_accesses(caller, accesses);
+    inlining_map.lock().record_accesses(caller, accesses);
 }
 
 fn check_recursion_limit<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index c2c71d90f0674..4ebfc23207088 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -702,9 +702,9 @@ fn typeck_item_bodies<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum
 {
     debug_assert!(crate_num == LOCAL_CRATE);
     Ok(tcx.sess.track_errors(|| {
-        for body_owner_def_id in tcx.body_owners() {
+        tcx.par_body_owners(|body_owner_def_id| {
             ty::maps::queries::typeck_tables_of::ensure(tcx, body_owner_def_id);
-        }
+        });
     })?)
 }
 
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 5b7d92944edf2..8af3a338dc194 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -83,6 +83,8 @@ This API is completely unstable and subject to change.
 #![feature(slice_sort_by_cached_key)]
 #![feature(never_type)]
 
+#![recursion_limit="256"]
+
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;
 extern crate syntax_pos;