commit 740cd296284e682d9d92bd638d266efccf817bbe
author Carl Shapiro <cshapiro@google.com> Fri Jul 09 17:41:26 2010 -0700
committer Carl Shapiro <cshapiro@google.com> Fri Jul 09 17:41:30 2010 -0700
tree 4ec589dd3e06735dd6bbe702e8edec59ed2d1c23
parent 99fc4560d75078b92daea33795489ac477e26cda

When aliasing a bitmap, use smallest available limit.

The original implementation of the bitmap aliasing routine chose the
conservative max value of the heap limit.  This is perfect for the
zygote but is oversized for application heaps that are not anywhere
near full.  Now the code consults the live bitmap and will use its max
value if it is smaller than the heap limit.

Change-Id: I7cf223efdeaed318922a8a5f9e147092e539da6c

vm/alloc/HeapSource.c

diff --git a/vm/alloc/HeapSource.c b/vm/alloc/HeapSource.c
index f55ccc5..1d82cfa 100644
--- a/vm/alloc/HeapSource.c
+++ b/vm/alloc/HeapSource.c
@@ -705,9 +705,10 @@
     HS_BOILERPLATE();
 
     assert(numHeaps == hs->numHeaps);
+    assert(hs->liveBits.max >= hs->markBits.max);
     for (i = 0; i < hs->numHeaps; ++i) {
         base = (uintptr_t)hs->heaps[i].base;
-        max = (uintptr_t)hs->heaps[i].limit - 1;
+        max = MIN((uintptr_t)hs->heaps[i].limit - 1, hs->liveBits.max);
         aliasBitmap(&liveBits[i], &hs->liveBits, base, max);
         aliasBitmap(&markBits[i], &hs->markBits, base, max);
     }