From: Simon Marlow <marlowsd@gmail.com>
Date: Sun, 8 Jun 2008 07:37:54 +0000 (+0000)
Subject: fix allocated blocks calculation, and add more sanity checks
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=a7f2a897bab20f05d4cf5fc8cdae328698c7fc82

fix allocated blocks calculation, and add more sanity checks
---

diff --git a/rts/sm/BlockAlloc.c b/rts/sm/BlockAlloc.c
index 3c12e19..0bffa82 100644
--- a/rts/sm/BlockAlloc.c
+++ b/rts/sm/BlockAlloc.c
@@ -306,23 +306,30 @@ allocGroup (nat n)
     bdescr *bd, *rem;
     nat ln;
 
-    // Todo: not true in multithreaded GC, where we use allocBlock_sync().
-    // ASSERT_SM_LOCK();
-
     if (n == 0) barf("allocGroup: requested zero blocks");
     
-    n_alloc_blocks += n;
-    if (n_alloc_blocks > hw_alloc_blocks) hw_alloc_blocks = n_alloc_blocks;
-
     if (n >= BLOCKS_PER_MBLOCK)
     {
-        bd = alloc_mega_group(BLOCKS_TO_MBLOCKS(n));
+        nat mblocks;
+
+        mblocks = BLOCKS_TO_MBLOCKS(n);
+
+        // n_alloc_blocks doesn't count the extra blocks we get in a
+        // megablock group.
+        n_alloc_blocks += mblocks * BLOCKS_PER_MBLOCK;
+        if (n_alloc_blocks > hw_alloc_blocks) hw_alloc_blocks = n_alloc_blocks;
+
+        bd = alloc_mega_group(mblocks);
         // only the bdescrs of the first MB are required to be initialised
         initGroup(bd);
+
         IF_DEBUG(sanity, checkFreeListSanity());
         return bd;
     }
     
+    n_alloc_blocks += n;
+    if (n_alloc_blocks > hw_alloc_blocks) hw_alloc_blocks = n_alloc_blocks;
+
     ln = log_2_ceil(n);
 
     while (free_list[ln] == NULL && ln < MAX_FREE_LIST) {
@@ -461,8 +468,6 @@ freeGroup(bdescr *p)
 
   ASSERT(p->free != (P_)-1);
 
-  n_alloc_blocks -= p->blocks;
-
   p->free = (void *)-1;  /* indicates that this block is free */
   p->step = NULL;
   p->gen_no = 0;
@@ -473,12 +478,21 @@ freeGroup(bdescr *p)
 
   if (p->blocks >= BLOCKS_PER_MBLOCK)
   {
+      nat mblocks;
+
+      mblocks = BLOCKS_TO_MBLOCKS(p->blocks);
       // If this is an mgroup, make sure it has the right number of blocks
-      ASSERT(p->blocks == MBLOCK_GROUP_BLOCKS(BLOCKS_TO_MBLOCKS(p->blocks)));
+      ASSERT(p->blocks == MBLOCK_GROUP_BLOCKS(mblocks));
+
+      n_alloc_blocks -= mblocks * BLOCKS_PER_MBLOCK;
+
       free_mega_group(p);
       return;
   }
 
+  ASSERT(n_alloc_blocks >= p->blocks);
+  n_alloc_blocks -= p->blocks;
+
   // coalesce forwards
   {
       bdescr *next;
diff --git a/rts/sm/BlockAlloc.h b/rts/sm/BlockAlloc.h
index 1472ac6..2d777f7 100644
--- a/rts/sm/BlockAlloc.h
+++ b/rts/sm/BlockAlloc.h
@@ -16,4 +16,7 @@ extern void checkFreeListSanity(void);
 nat         countFreeList(void);
 #endif
 
+lnat n_alloc_blocks;   // currently allocated blocks
+lnat hw_alloc_blocks;  // high-water allocated blocks
+
 #endif /* BLOCK_ALLOC_H */
diff --git a/rts/sm/Storage.c b/rts/sm/Storage.c
index d37a076..b76fcf4 100644
--- a/rts/sm/Storage.c
+++ b/rts/sm/Storage.c
@@ -1308,6 +1308,9 @@ memInventory (rtsBool show)
 #define MB(n) (((n) * BLOCK_SIZE_W) / ((1024*1024)/sizeof(W_)))
 
   leak = live_blocks + free_blocks != mblocks_allocated * BLOCKS_PER_MBLOCK;
+
+  ASSERT(n_alloc_blocks == live_blocks);
+
   if (show || leak)
   {
       if (leak) {