update libports-reduce-overhead.patch

1 files changed, 22 insertions, 10 deletions

diff --git a/debian/patches/libports-reduce-overhead.patch b/debian/patches/libports-reduce-overhead.patch
index 624e2672..968673ba 100644
--- a/debian/patches/libports-reduce-overhead.patch
+++ b/debian/patches/libports-reduce-overhead.patch
@@ -1,4 +1,4 @@
-commit a7c6b5d7b1b669355439361a2a8eecf52dc78538
+commit 97737d1ee3ce95e45a1a4aa636cc2e11a106a9f5
 Author: Justus Winter <4winter@informatik.uni-hamburg.de>
 Date:   Sat Apr 26 12:20:20 2014 +0200
 
@@ -14,20 +14,23 @@ Date:   Sat Apr 26 12:20:20 2014 +0200
     _ports_bucket_class_iterate implements both ports_bucket_iterate and
     ports_class_iterate.  For this change might make ports_class_iterate
     less efficient memory-wise if the number of ports belonging to the
-    class is low with respect to the number of ports in the bucket.
-    However, the array representation is more compact.  Furthermore a
-    survey of the Hurd code revealed that ports_class_iterate is rarely
-    used, while ports_bucket_iterate is used more often, most prominently
-    in paging code.
+    class is low with respect to the number of ports in the bucket.  If
+    this happens, we allocate too much.  Alleviate this by releasing
+    unused memory.
+    
+    On the other hand, the array representation is more compact.
+    Furthermore a survey of the Hurd code revealed that
+    ports_class_iterate is rarely used, while ports_bucket_iterate is used
+    more often, most prominently in paging code.
     
     * libports/bucket-iterate.c (_ports_bucket_class_iterate): Use an
     array instead of a linked list.
 
 diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c
-index dc1c7b1..8e6bdc4 100644
+index dc1c7b1..498cf13 100644
 --- a/libports/bucket-iterate.c
 +++ b/libports/bucket-iterate.c
-@@ -31,40 +31,45 @@ _ports_bucket_class_iterate (struct port_bucket *bucket,
+@@ -31,40 +31,54 @@ _ports_bucket_class_iterate (struct port_bucket *bucket,
  {
    /* This is obscenely ineffecient.  ihash and ports need to cooperate
       more closely to do it efficiently. */
@@ -38,7 +41,7 @@ index dc1c7b1..8e6bdc4 100644
 -    } *list = 0;
 -  struct item *i, *nxt;
 +  void **p;
-+  size_t i, n;
++  size_t i, n, nr_items;
    error_t err;
  
    pthread_mutex_lock (&_ports_lock);
@@ -49,7 +52,8 @@ index dc1c7b1..8e6bdc4 100644
 +      return 0;
 +    }
 +
-+  p = malloc (bucket->htable.nr_items * sizeof *p);
++  nr_items = bucket->htable.nr_items;
++  p = malloc (nr_items * sizeof *p);
 +  if (p == NULL)
 +    return ENOMEM;
 +
@@ -72,6 +76,14 @@ index dc1c7b1..8e6bdc4 100644
      }
    pthread_mutex_unlock (&_ports_lock);
  
++  if (n != nr_items)
++    {
++      /* We allocated too much.  Release unused memory.  */
++      void **new = realloc (p, n * sizeof *p);
++      if (new)
++        p = new;
++    }
++
    err = 0;
 -  for (i = list; i; i = nxt)
 +  for (i = 0; i < n; i++)