* cygheap.h (struct _cmalloc_entry): Define b as unsigned rather than

	DWORD.
	(NBUCKETS): Define here as constant value.
	(struct init_cygheap): Add bucket_val member.  Define size of bucket_val
	and buckets using NBUCKETS.
	* cygheap.cc (NBUCKETS): Drop definition here.
	(cygheap_init): Initialize cygheap->bucket_val.  Add comment to explain
	what we do and why.
	(_cmalloc): Simplify bit bucket search using cygheap->bucket_val.  Drop
	local variable sz.  Fetch size of block from cygheap->bucket_val.
	(_cfree): Define b as unsigned.
	(_crealloc): Fetch size of block from cygheap->bucket_val.

3 files changed, 44 insertions, 9 deletions

diff --git a/winsup/cygwin/ChangeLog.64bit b/winsup/cygwin/ChangeLog.64bit
index b8ee5fc9d..5dd2adac6 100644
--- a/winsup/cygwin/ChangeLog.64bit
+++ b/winsup/cygwin/ChangeLog.64bit
@@ -1,3 +1,18 @@
+2013-04-04  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygheap.h (struct _cmalloc_entry): Define b as unsigned rather than
+	DWORD.
+	(NBUCKETS): Define here as constant value.
+	(struct init_cygheap): Add bucket_val member.  Define size of bucket_val
+	and buckets using NBUCKETS.
+	* cygheap.cc (NBUCKETS): Drop definition here.
+	(cygheap_init): Initialize cygheap->bucket_val.  Add comment to explain
+	what we do and why.
+	(_cmalloc): Simplify bit bucket search using cygheap->bucket_val.  Drop
+	local variable sz.  Fetch size of block from cygheap->bucket_val.
+	(_cfree): Define b as unsigned.
+	(_crealloc): Fetch size of block from cygheap->bucket_val.
+
 2013-04-02  Алексей Павлов <alexpux@gmail.com>
 
 	* fhandler_disk_file.cc (fhandler_disk_file::ftruncate): Add missed
diff --git a/winsup/cygwin/cygheap.cc b/winsup/cygwin/cygheap.cc
index 6b068008f..5d41e18c6 100644
--- a/winsup/cygwin/cygheap.cc
+++ b/winsup/cygwin/cygheap.cc
@@ -65,7 +65,6 @@ static NO_COPY uint32_t nthreads;
 
 #define THREADLIST_CHUNK 256
 
-#define NBUCKETS (sizeof (cygheap->buckets) / sizeof (cygheap->buckets[0]))
 #define to_cmalloc(s) ((_cmalloc_entry *) (((char *) (s)) - offsetof (_cmalloc_entry, data)))
 
 #define CFMAP_OPTIONS (SEC_RESERVE | PAGE_READWRITE)
@@ -261,6 +260,21 @@ cygheap_init ()
 					 sizeof (*cygheap));
       cygheap_max = cygheap;
       _csbrk (sizeof (*cygheap));
+      /* Initialize bucket_val.  The value is the max size of a block
+         fitting into the bucket.  The values are powers of two and their
+	 medians: 12, 16, 24, 32, 48, 64, ...  On 64 bit, start with 24 to
+	 accommodate bigger size of struct cygheap_entry.
+	 With NBUCKETS == 40, the maximum block size is 6291456/12582912.
+	 The idea is to have better matching bucket sizes (not wasting
+	 space) without trading in performance compared to the old powers
+	 of 2 method. */
+#ifdef __x86_64__
+      unsigned sz[2] = { 16, 24 };	/* sizeof cygheap_entry == 16 */
+#else
+      unsigned sz[2] = { 8, 12 };	/* sizeof cygheap_entry == 8 */
+#endif
+      for (unsigned b = 1; b < NBUCKETS; b++, sz[b & 1] <<= 1)
+	cygheap->bucket_val[b] = sz[b & 1];
       /* Default locale settings. */
       cygheap->locale.mbtowc = __utf8_mbtowc;
       cygheap->locale.wctomb = __utf8_wctomb;
@@ -285,11 +299,13 @@ static void *__reg1
 _cmalloc (unsigned size)
 {
   _cmalloc_entry *rvc;
-  unsigned b, sz;
+  unsigned b;
 
-  /* Calculate "bit bucket" and size as a power of two. */
-  for (b = 3, sz = 8; sz && sz < size; b++, sz <<= 1)
+  /* Calculate "bit bucket". */
+  for (b = 1; b < NBUCKETS && cygheap->bucket_val[b] < size; b++)
     continue;
+  if (b >= NBUCKETS)
+    return NULL;
 
   cygheap_protect.acquire ();
   if (cygheap->buckets[b])
@@ -300,7 +316,8 @@ _cmalloc (unsigned size)
     }
   else
     {
-      rvc = (_cmalloc_entry *) _csbrk (sz + sizeof (_cmalloc_entry));
+      rvc = (_cmalloc_entry *) _csbrk (cygheap->bucket_val[b]
+				       + sizeof (_cmalloc_entry));
       if (!rvc)
 	{
 	  cygheap_protect.release ();
@@ -320,7 +337,7 @@ _cfree (void *ptr)
 {
   cygheap_protect.acquire ();
   _cmalloc_entry *rvc = to_cmalloc (ptr);
-  DWORD b = rvc->b;
+  unsigned b = rvc->b;
   rvc->ptr = cygheap->buckets[b];
   cygheap->buckets[b] = (char *) rvc;
   cygheap_protect.release ();
@@ -334,7 +351,7 @@ _crealloc (void *ptr, unsigned size)
     newptr = _cmalloc (size);
   else
     {
-      unsigned oldsize = 1 << to_cmalloc (ptr)->b;
+      unsigned oldsize = cygheap->bucket_val[to_cmalloc (ptr)->b];
       if (size <= oldsize)
 	return ptr;
       newptr = _cmalloc (size);
diff --git a/winsup/cygwin/cygheap.h b/winsup/cygwin/cygheap.h
index bdc3a1144..bb2d20a3e 100644
--- a/winsup/cygwin/cygheap.h
+++ b/winsup/cygwin/cygheap.h
@@ -18,7 +18,7 @@ struct _cmalloc_entry
 {
   union
   {
-    DWORD b;
+    unsigned b;
     char *ptr;
   };
   struct _cmalloc_entry *prev;
@@ -365,10 +365,13 @@ struct mini_cygheap
   cygheap_locale locale;
 };
 
+#define NBUCKETS 40
+
 struct init_cygheap: public mini_cygheap
 {
   _cmalloc_entry *chain;
-  char *buckets[32];
+  unsigned bucket_val[NBUCKETS];
+  char *buckets[NBUCKETS];
   WCHAR installation_root[PATH_MAX];
   UNICODE_STRING installation_key;
   WCHAR installation_key_buf[18];