diff --git a/libvips/include/vips/gate.h b/libvips/include/vips/gate.h
index d499950d..7d2e1928 100644
--- a/libvips/include/vips/gate.h
+++ b/libvips/include/vips/gate.h
@@ -37,36 +37,6 @@ extern "C" {
 
 #include <vips/vips.h>
 
-#define VIPS_GATE_SIZE (10000)
-
-/* A set of timing records. i is the index of the next slot we fill. 
- */
-typedef struct _VipsThreadGateBlock {
-	struct _VipsThreadGateBlock *prev;
-
-	gint64 time[VIPS_GATE_SIZE];
-	int i;
-} VipsThreadGateBlock; 
-
-/* What we track for each gate-name.
- */
-typedef struct _VipsThreadGate {
-	const char *name;
-	VipsThreadGateBlock *start;
-	VipsThreadGateBlock *stop;
-} VipsThreadGate; 
-
-/* One of these in per-thread private storage. 
- */
-
-typedef struct _VipsThreadProfile {
-	/*< private >*/
-
-	const char *name;
-	GThread *thread;
-	GHashTable *gates;
-} VipsThreadProfile; 
-
 #define VIPS_GATE_START( NAME ) \
 G_STMT_START { \
 	if( vips__thread_profile ) \
diff --git a/libvips/iofuncs/gate.c b/libvips/iofuncs/gate.c
index 55241f84..95d88762 100644
--- a/libvips/iofuncs/gate.c
+++ b/libvips/iofuncs/gate.c
@@ -42,6 +42,36 @@
 #include <vips/vips.h>
 #include <vips/internal.h>
 
+#define VIPS_GATE_SIZE (1000)
+
+/* A set of timing records. i is the index of the next slot we fill. 
+ */
+typedef struct _VipsThreadGateBlock {
+	struct _VipsThreadGateBlock *prev;
+
+	gint64 time[VIPS_GATE_SIZE];
+	int i;
+} VipsThreadGateBlock; 
+
+/* What we track for each gate-name.
+ */
+typedef struct _VipsThreadGate {
+	const char *name;
+	VipsThreadGateBlock *start;
+	VipsThreadGateBlock *stop;
+} VipsThreadGate; 
+
+/* One of these in per-thread private storage. 
+ */
+
+typedef struct _VipsThreadProfile {
+	/*< private >*/
+
+	const char *name;
+	GThread *thread;
+	GHashTable *gates;
+} VipsThreadProfile; 
+
 gboolean vips__thread_profile = FALSE;
 
 static GPrivate *vips_thread_profile_key = NULL;
diff --git a/tools/vipsprofile.py b/tools/vipsprofile.py
index 22d37ad5..483ce9f4 100755
--- a/tools/vipsprofile.py
+++ b/tools/vipsprofile.py
@@ -31,24 +31,25 @@ def read_times(rf):
         match = re.match('[0-9]+ ', rf.line)
         if not match:
             break
-        times.append([int(x) for x in re.split(' ', rf.line.rstrip())])
+        times += [int(x) for x in re.split(' ', rf.line.rstrip())]
         rf.getnext()
 
     return times[::-1]
 
 class Event:
-    def __init__(self, thread_name, thread_addr, gate_name, start, end):
+    def __init__(self, thread_name, thread_addr, gate_name, start, stop):
         self.thread_name = thread_name
         self.thread_addr = thread_addr
         self.gate_name = gate_name
         self.start = start
-        self.end = end
+        self.stop = stop
 
         if re.match(': work', gate_name):
             self.work = True
         if re.match(': wait', gate_name):
             self.wait = True
 
+events = []
 with ReadFile('vips-profile.txt') as rf:
     while rf:
         match = re.match('thread: (.*) \(0x([0-9a-f]+)\)', rf.line)
@@ -81,3 +82,11 @@ with ReadFile('vips-profile.txt') as rf:
 
             if len(start) != len(stop):
                 print 'start and stop length mismatch'
+
+            for a, b in zip(start, stop):
+                event = Event(thread_name, thread_addr, gate_name, a, b)
+                events.append(event)
+
+events.sort(lambda x, y: cmp(x.start, y.start))
+
+print 'loaded %d events' % len(events)