Page allocator moved from pools to IO loops.

The resource pool system is highly hierarchical and keeping spare pages
in pools leads to unnecessarily complex memory management.

Loops have a flat hiearchy, at least for now, and it is therefore much
easier to keep care of pages, especially in cases of excessive virtual memory
fragmentation.

4 files changed, 10 insertions, 78 deletions

diff --git a/lib/mempool.c b/lib/mempool.c
index 8f300b81..ed3ae8de 100644
--- a/lib/mempool.c
+++ b/lib/mempool.c
@@ -130,7 +130,7 @@ lp_alloc(linpool *m, uint size)
 	    {
 	      /* Need to allocate a new chunk */
 	      if (m->use_pages)
-		c = alloc_page(m->p);
+		c = alloc_page();
 	      else
 		c = xmalloc(sizeof(struct lp_chunk) + m->chunk_size);
 
@@ -271,7 +271,7 @@ lp_free(resource *r)
     {
       c = d->next;
       if (m->use_pages)
-	free_page(m->p, d);
+	free_page(d);
       else
 	xfree(d);
     }
diff --git a/lib/resource.c b/lib/resource.c
index c847d41a..d98cd4ff 100644
--- a/lib/resource.c
+++ b/lib/resource.c
@@ -30,14 +30,6 @@
  * is freed upon shutdown of the module.
  */
 
-struct pool_pages {
-  uint free;
-  uint used;
-  void *ptr[0];
-};
-
-#define POOL_PAGES_MAX	((page_size - sizeof(struct pool_pages)) / sizeof (void *))
-
 static void pool_dump(resource *);
 static void pool_free(resource *);
 static resource *pool_lookup(resource *, unsigned long);
@@ -54,9 +46,6 @@ static struct resclass pool_class = {
 
 pool root_pool;
 
-void *alloc_sys_page(void);
-int free_sys_page(void *);
-
 static int indent;
 
 /**
@@ -103,16 +92,6 @@ pool_free(resource *P)
       r = rr;
     }
 
-  if (p->pages)
-    {
-      ASSERT_DIE(!p->pages->used);
-
-      for (uint i = 0; i < p->pages->free; i++)
-	free_sys_page(p->pages->ptr[i]);
-
-      free_sys_page(p->pages);
-    }
-
   pool_parent = parent;
 }
 
@@ -185,9 +164,6 @@ pool_memsize_locked(pool *p)
   WALK_LIST(r, p->inside)
     sum += rmemsize(r);
 
-  if (p->pages)
-    sum += page_size * (p->pages->used + p->pages->free + 1);
-
   return sum;
 }
 
@@ -551,49 +527,6 @@ mb_free(void *m)
   rfree(b);
 }
 
-void *
-alloc_page(pool *p)
-{
-  if (!p->pages)
-  {
-    p->pages = alloc_sys_page();
-    p->pages->free = 0;
-    p->pages->used = 1;
-  }
-  else
-    p->pages->used++;
-
-  if (p->pages->free)
-  {
-    void *ptr = p->pages->ptr[--p->pages->free];
-    bzero(ptr, page_size);
-    return ptr;
-  }
-  else
-    return alloc_sys_page();
-}
-
-void
-free_page(pool *p, void *ptr)
-{
-  ASSERT_DIE(p->pages);
-  p->pages->used--;
-
-  ASSERT_DIE(p->pages->free <= POOL_PAGES_MAX);
-
-  if (p->pages->free == POOL_PAGES_MAX)
-  {
-    const unsigned long keep = POOL_PAGES_MAX / 4;
-
-    for (uint i = keep; i < p->pages->free; i++)
-      free_sys_page(p->pages->ptr[i]);
-
-    p->pages->free = keep;
-  }
-
-  p->pages->ptr[p->pages->free++] = ptr;
-}
-
 
 #define STEP_UP(x) ((x) + (x)/2 + 4)
 
diff --git a/lib/resource.h b/lib/resource.h
index 7adde493..9d7dae69 100644
--- a/lib/resource.h
+++ b/lib/resource.h
@@ -108,8 +108,8 @@ void buffer_realloc(void **buf, unsigned *size, unsigned need, unsigned item_siz
 extern long page_size;
 
 /* Allocator of whole pages; for use in slabs and other high-level allocators. */
-void *alloc_page(pool *);
-void free_page(pool *, void *);
+void *alloc_page(void);
+void free_page(void *);
 #define PAGE_HEAD(x)	((void *) (((intptr_t) (x)) & ~(page_size-1)))
 
 #ifdef HAVE_LIBDMALLOC
diff --git a/lib/slab.c b/lib/slab.c
index 6348e29b..32e241e4 100644
--- a/lib/slab.c
+++ b/lib/slab.c
@@ -269,7 +269,7 @@ no_partial:
       s->num_empty_heads--;
       goto okay;
     }
-  h = alloc_page(s->p);
+  h = alloc_page();
 #ifdef POISON
   memset(h, 0xba, page_size);
 #endif
@@ -332,7 +332,7 @@ sl_free(slab *s, void *oo)
 #ifdef POISON
 	memset(h, 0xde, page_size);
 #endif
-	free_page(s->p, h);
+	free_page(h);
       }
       else
 	{
@@ -349,11 +349,11 @@ slab_free(resource *r)
   struct sl_head *h, *g;
 
   WALK_LIST_DELSAFE(h, g, s->empty_heads)
-    free_page(s->p, h);
+    free_page(h);
   WALK_LIST_DELSAFE(h, g, s->partial_heads)
-    free_page(s->p, h);
+    free_page(h);
   WALK_LIST_DELSAFE(h, g, s->full_heads)
-    free_page(s->p, h);
+    free_page(h);
 }
 
 static void
@@ -386,8 +386,7 @@ slab_memsize(resource *r)
   WALK_LIST(h, s->full_heads)
     heads++;
 
-//  return ALLOC_OVERHEAD + sizeof(struct slab) + heads * (ALLOC_OVERHEAD + page_size);
-  return ALLOC_OVERHEAD + sizeof(struct slab); /* The page sizes are accounted for in the pool */
+  return ALLOC_OVERHEAD + sizeof(struct slab) + heads * page_size;
 }
 
 static resource *