* hack dietlibc's allocator. release small block to OS.

 * allocation behavior dirty hack for dietlibc.
   Avoid allocate 64byte slot, use 128byte slot instead.
   Thus, they share same memory block.
 * save about 400mb for ptt.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@3519 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

3 files changed, 32 insertions, 0 deletions

diff --git a/mbbsd/alloc.c b/mbbsd/alloc.c
index 06b84177..de676ce4 100644
--- a/mbbsd/alloc.c
+++ b/mbbsd/alloc.c
@@ -56,6 +56,9 @@ static void REGPARM(1) *do_mmap(size_t size) {
 
 static __alloc_t* __small_mem[8];
 
+static int smallalloc[8];
+static int smallalloc_max[8];
+
 #define __SMALL_NR(i)		(MEM_BLOCK_SIZE/(i))
 
 #define __MIN_SMALL_SIZE	__SMALL_NR(256)		/*   16 /   32 */
@@ -88,6 +91,17 @@ static void REGPARM(2) __small_free(void*_ptr,size_t _size) {
 
   ptr->next=__small_mem[idx];
   __small_mem[idx]=ptr;
+
+  smallalloc[idx]--;
+
+  if (MEM_BLOCK_SIZE == PAGE_SIZE &&
+	  smallalloc[idx] == 0 &&
+	  smallalloc_max[idx] < __SMALL_NR(size)) {
+      __alloc_t* p = __small_mem[idx];
+      __alloc_t* ph = p - (size_t)p%PAGE_SIZE;
+      munmap(ph, MEM_BLOCK_SIZE);
+      __small_mem[idx] = 0;
+  }
 }
 
 static void* REGPARM(1) __small_malloc(size_t _size) {
@@ -119,6 +133,10 @@ static void* REGPARM(1) __small_malloc(size_t _size) {
   __small_mem[idx]=ptr->next;
   ptr->next=0;
 
+  smallalloc[idx]++;
+  if(smallalloc[idx] > smallalloc_max[idx])
+      smallalloc_max[idx] = smallalloc[idx];
+
   return ptr;
 }
 
diff --git a/mbbsd/fav.c b/mbbsd/fav.c
index eb9a40dc..e4b0e74e 100644
--- a/mbbsd/fav.c
+++ b/mbbsd/fav.c
@@ -524,7 +524,12 @@ int fav_load(void)
 
     if ((frp = fopen(buf, "r")) == NULL)
 	return -1;
+#ifdef CRITICAL_MEMORY
+    // kcwu: dirty hack, avoid 64byte slot. use 128 instead.
+    fp = (fav_t *)fav_malloc(sizeof(fav_t)+64);
+#else
     fp = (fav_t *)fav_malloc(sizeof(fav_t));
+#endif
     fav_number = 0;
     fread(&version, sizeof(version), 1, frp);
     // if (version != FAV_VERSION) { ... }
diff --git a/mbbsd/pmore.c b/mbbsd/pmore.c
index 26f73a38..dd22ed60 100644
--- a/mbbsd/pmore.c
+++ b/mbbsd/pmore.c
@@ -809,7 +809,16 @@ mf_parseHeaders()
 
 	// p is pointing at a new line. (\n)
 	l = (int)(p - pb);
+#ifdef CRITICAL_MEMORY
+	// kcwu: dirty hack, avoid 64byte slot. use 128byte slot instead.
+	if (l<100) {
+	    p = (unsigned char*) malloc (100+1);
+	} else {
+	    p = (unsigned char*) malloc (l+1);
+	}
+#else
 	p = (unsigned char*) malloc (l+1);
+#endif
 	fh.headers[i] = p;
 	memcpy(p, pb, l);
 	p[l] = 0;