about summary refs log tree commit diff
diff options
context:
space:
mode:
authorbors <bors@rust-lang.org>2019-04-15 07:12:16 +0000
committerbors <bors@rust-lang.org>2019-04-15 07:12:16 +0000
commit1edb01b7afe758dc79740e72fb8b9909402c9620 (patch)
treef677854cd24560985843ac2d581e9e7cd14e0744
parenta55f6be4286991437659acb8506466e8d637ac51 (diff)
parent304a7be7a875e76a040bce0d1247d17d475e460a (diff)
downloadrust-1edb01b7afe758dc79740e72fb8b9909402c9620.tar.gz
rust-1edb01b7afe758dc79740e72fb8b9909402c9620.zip
Auto merge of #59626 - nnethercote:DepGraph-1.02x, r=Zoxc
Reduce the `DepNode` pre-allocation ratio.

A code size of increase of 15% is overly generous. 2% is more realistic.

This change reduces peak memory size by 20+ MiB on some workloads.

r? @Zoxc
-rw-r--r--src/librustc/dep_graph/graph.rs5
1 files changed, 3 insertions, 2 deletions
diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs
index db81a9d826f..1ecc580d8c5 100644
--- a/src/librustc/dep_graph/graph.rs
+++ b/src/librustc/dep_graph/graph.rs
@@ -992,8 +992,9 @@ impl CurrentDepGraph {
 
         // Pre-allocate the dep node structures. We over-allocate a little so
         // that we hopefully don't have to re-allocate during this compilation
-        // session.
-        let new_node_count_estimate = (prev_graph_node_count * 115) / 100;
+        // session. The over-allocation is 2% plus a small constant to account
+        // for the fact that in very small crates 2% might not be enough.
+        let new_node_count_estimate = (prev_graph_node_count * 102) / 100 + 200;
 
         CurrentDepGraph {
             data: IndexVec::with_capacity(new_node_count_estimate),