commit 8fefd17abb546caae827649b42dbd789fd85cbfc
author Petr Hosek <phosek@google.com> Wed Nov 30 02:34:46 2022 +0000
committer Copybara-Service <copybara-worker@google.com> Tue Nov 29 18:37:20 2022 -0800
tree f3502f586460d1d4f4b3ac3b3b1964260e826ae8
parent 9d6a19892a113fc0ede6062354fb61437909710c

[scudo] Do not consider releasing unallocated pages

We already know that there are no free blocks above Region->AllocatedUser.
This results in a smaller RegionPageMap and faster releaseFreeMemoryToOS.

Patch By: fabio-d
Differential Revision: https://reviews.llvm.org/D138794

GitOrigin-RevId: 12e20a446e4df75a6aa147dd322ba6a34545c2bc

lib/scudo/standalone/primary64.h

diff --git a/lib/scudo/standalone/primary64.h b/lib/scudo/standalone/primary64.h
index d06a047..b653bc8 100644
--- a/lib/scudo/standalone/primary64.h
+++ b/lib/scudo/standalone/primary64.h
@@ -691,7 +691,8 @@
     const uptr GroupSize = (1U << GroupSizeLog);
     const uptr AllocatedUserEnd = Region->AllocatedUser + Region->RegionBeg;
     ReleaseRecorder Recorder(Region->RegionBeg, &Region->Data);
-    PageReleaseContext Context(BlockSize, RegionSize, /*NumberOfRegions=*/1U);
+    PageReleaseContext Context(BlockSize, Region->AllocatedUser,
+                               /*NumberOfRegions=*/1U);
 
     const uptr CompactPtrBase = getCompactPtrBaseByClassId(ClassId);
     auto DecompactPtr = [CompactPtrBase](CompactPtrT CompactPtr) {