From 03f1e6a2aa8aa1d5aef79a33a243372a457f0fa2 Mon Sep 17 00:00:00 2001
From: Alan Wu <XrXr@users.noreply.github.com>
Date: Tue, 29 Nov 2022 15:37:29 -0500
Subject: [PATCH] YJIT: Fix IseqPayload::pages memory bloat

HashSet::clear() doesn't deallocate the backing buffer and shrink the
capacity. Replace with a 0-capcity set instead so we reclaim some memory
each code GC.
---
 yjit/src/asm/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/yjit/src/asm/mod.rs b/yjit/src/asm/mod.rs
index 417d664b07..47e2dca137 100644
--- a/yjit/src/asm/mod.rs
+++ b/yjit/src/asm/mod.rs
@@ -574,7 +574,7 @@ impl CodeBlock {
         });
         // Avoid accumulating freed pages for future code GC
         for_each_off_stack_iseq_payload(|iseq_payload: &mut IseqPayload| {
-            iseq_payload.pages.clear();
+            iseq_payload.pages = std::collections::HashSet::default();
         });
         // Outlined code generated by CodegenGlobals::init() should also be kept.
         for page in CodegenGlobals::get_ocb_pages() {