[PATCH] D73658: [scudo][standalone] Revert some perf-degrading changes

[Kostya Kortchinsky via Phabricator via llvm-commits]

cryptoad created this revision.
Herald added projects: Sanitizers, LLVM.
Herald added subscribers: llvm-commits, Sanitizers.

A couple of seemingly innocuous changes ended up having a large impact
on the 32-bit performance. I still have to make those configurable at
some point, but right now it will have to do.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73658

Files:
  compiler-rt/lib/scudo/standalone/primary32.h
  compiler-rt/lib/scudo/standalone/primary64.h


Index: compiler-rt/lib/scudo/standalone/primary64.h
===================================================================
--- compiler-rt/lib/scudo/standalone/primary64.h
+++ compiler-rt/lib/scudo/standalone/primary64.h
@@ -87,7 +87,8 @@
       // limit is mostly arbitrary and based on empirical observations.
       // TODO(kostyak): make the lower limit a runtime option
       Region->CanRelease = (ReleaseToOsInterval >= 0) &&
-                           (getSizeByClassId(I) >= (PageSize / 64));
+                           (I != SizeClassMap::BatchClassId) &&
+                           (getSizeByClassId(I) >= (PageSize / 32));
       Region->RandState = getRandomU32(&Seed);
     }
     ReleaseToOsIntervalMs = ReleaseToOsInterval;
Index: compiler-rt/lib/scudo/standalone/primary32.h
===================================================================
--- compiler-rt/lib/scudo/standalone/primary32.h
+++ compiler-rt/lib/scudo/standalone/primary32.h
@@ -74,7 +74,8 @@
       Sci->RandState = getRandomU32(&Seed);
       // See comment in the 64-bit primary about releasing smaller size classes.
       Sci->CanRelease = (ReleaseToOsInterval >= 0) &&
-                        (getSizeByClassId(I) >= (PageSize / 64));
+                        (I != SizeClassMap::BatchClassId) &&
+                        (getSizeByClassId(I) >= (PageSize / 32));
     }
     ReleaseToOsIntervalMs = ReleaseToOsInterval;
   }


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