File Support-Dynamic-triple-double-buffering.patch of Package mutter

Overview Repositories Revisions Requests Users Attributes Meta

File Support-Dynamic-triple-double-buffering.patch of Package mutter (Revision ca30a3cacfdf47d5c4e7c2293aa6615a)

Currently displaying revision ca30a3cacfdf47d5c4e7c2293aa6615a , Show latest

From: Daniel van Vugt <daniel.van.vugt@canonical.com>
Date: Wed, 10 Nov 2021 18:55:53 +0800
Subject: Support Dynamic triple/double buffering

Use triple buffering if and when the previous frame is running late.
This means the next frame will be dispatched on time instead of also starting
late.

It also triggers a GPU clock boost if deemed necessary by the driver.
Although frequency scaling is not required to get a performance gain here
because even a fixed frequency GPU will benefit from not over-sleeping anymore.
If the previous frame is not running late then we stick to double buffering so
there's no latency penalty when the system is able to maintain full frame rate.

Formatted for Debian (as of 43.3-51-ga6f23c151c) with:
git remote add vanvugt git@ssh.gitlab.gnome.org:vanvugt/mutter.git
git fetch vanvugt
git merge --squash -e vanvugt/triple-buffering-v4
And then git commit but using all this as the header instead of what
git suggests. Also add Gbp-Pq: Topic debian

Origin: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1441
Last-Update: 2023-02-16
---
 clutter/clutter/clutter-frame-clock.c             | 217 ++++++++++++++----
 clutter/clutter/clutter-frame-clock.h             |  11 +-
 clutter/clutter/clutter-frame-private.h           |   1 +
 clutter/clutter/clutter-frame.c                   |  13 ++
 clutter/clutter/clutter-frame.h                   |   7 +
 clutter/clutter/clutter-stage-view.c              |   5 +-
 cogl/cogl/cogl-onscreen-private.h                 |   3 +
 cogl/cogl/cogl-onscreen.c                         |   8 +
 src/backends/meta-stage-impl.c                    |   2 +
 src/backends/native/meta-cursor-renderer-native.c | 144 ++----------
 src/backends/native/meta-kms-crtc.c               |  21 ++
 src/backends/native/meta-kms-crtc.h               |   3 +
 src/backends/native/meta-kms-impl-device-atomic.c |   9 +-
 src/backends/native/meta-kms-impl-device-simple.c |  38 +++-
 src/backends/native/meta-kms-impl-device.c        |  14 ++
 src/backends/native/meta-kms-page-flip.c          |   3 +
 src/backends/native/meta-kms-update-private.h     |   6 +
 src/backends/native/meta-kms-update.c             |  51 ++++-
 src/backends/native/meta-kms.c                    | 113 ++++++++-
 src/backends/native/meta-kms.h                    |  12 +
 src/backends/native/meta-onscreen-native.c        | 264 +++++++++++++++-------
 src/backends/native/meta-onscreen-native.h        |   2 +
 src/backends/native/meta-renderer-native.c        |  34 ++-
 src/backends/native/meta-swap-chain.c             | 149 ++++++++++++
 src/backends/native/meta-swap-chain.h             |  48 ++++
 src/meson.build                                   |   2 +
 src/tests/native-kms-render.c                     |  79 +++++--
 27 files changed, 979 insertions(+), 280 deletions(-)
 create mode 100644 src/backends/native/meta-swap-chain.c
 create mode 100644 src/backends/native/meta-swap-chain.h

diff --git a/clutter/clutter/clutter-frame-clock.c b/clutter/clutter/clutter-frame-clock.c
index e4d0fb9..42242a6 100644
--- a/clutter/clutter/clutter-frame-clock.c
+++ b/clutter/clutter/clutter-frame-clock.c
@@ -35,6 +35,15 @@ enum
 
 static guint signals[N_SIGNALS];
 
+typedef enum
+{
+  TRIPLE_BUFFERING_MODE_NEVER,
+  TRIPLE_BUFFERING_MODE_AUTO,
+  TRIPLE_BUFFERING_MODE_ALWAYS,
+} TripleBufferingMode;
+
+static TripleBufferingMode triple_buffering_mode = TRIPLE_BUFFERING_MODE_AUTO;
+
 #define SYNC_DELAY_FALLBACK_FRACTION 0.875
 
 typedef struct _ClutterFrameListener
@@ -55,8 +64,9 @@ typedef enum _ClutterFrameClockState
   CLUTTER_FRAME_CLOCK_STATE_INIT,
   CLUTTER_FRAME_CLOCK_STATE_IDLE,
   CLUTTER_FRAME_CLOCK_STATE_SCHEDULED,
-  CLUTTER_FRAME_CLOCK_STATE_DISPATCHING,
-  CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED,
+  CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE,
+  CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED,
+  CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO,
 } ClutterFrameClockState;
 
 struct _ClutterFrameClock
@@ -73,6 +83,7 @@ struct _ClutterFrameClock
 
   ClutterFrameClockState state;
   int64_t last_dispatch_time_us;
+  int64_t prev_last_dispatch_time_us;
   int64_t last_dispatch_lateness_us;
   int64_t last_presentation_time_us;
   int64_t next_update_time_us;
@@ -86,6 +97,9 @@ struct _ClutterFrameClock
   int64_t vblank_duration_us;
   /* Last KMS buffer submission time. */
   int64_t last_flip_time_us;
+  int64_t prev_last_flip_time_us;
+
+  ClutterFrameHint last_flip_hints;
 
   /* Last time we promoted short term durations to long term ones */
   int64_t longterm_promotion_us;
@@ -237,6 +251,12 @@ void
 clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock,
                                       ClutterFrameInfo  *frame_info)
 {
+#ifdef CLUTTER_ENABLE_DEBUG
+  const char *debug_state =
+    frame_clock->state == CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO ?
+    "Triple buffering" : "Double buffering";
+#endif
+
   COGL_TRACE_BEGIN_SCOPED (ClutterFrameClockNotifyPresented,
                            "Frame Clock (presented)");
 
@@ -288,18 +308,38 @@ clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock,
       frame_info->gpu_rendering_duration_ns != 0)
     {
       int64_t dispatch_to_swap_us, swap_to_rendering_done_us, swap_to_flip_us;
+      int64_t dispatch_time_us = 0, flip_time_us = 0;
+
+      switch (frame_clock->state)
+        {
+        case CLUTTER_FRAME_CLOCK_STATE_INIT:
+        case CLUTTER_FRAME_CLOCK_STATE_IDLE:
+        case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+          g_warn_if_reached ();
+          G_GNUC_FALLTHROUGH;
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+          dispatch_time_us = frame_clock->last_dispatch_time_us;
+          flip_time_us = frame_clock->last_flip_time_us;
+          break;
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
+          dispatch_time_us = frame_clock->prev_last_dispatch_time_us;
+          flip_time_us = frame_clock->prev_last_flip_time_us;
+          break;
+        }
 
       dispatch_to_swap_us =
         frame_info->cpu_time_before_buffer_swap_us -
-        frame_clock->last_dispatch_time_us;
+        dispatch_time_us;
       swap_to_rendering_done_us =
         frame_info->gpu_rendering_duration_ns / 1000;
       swap_to_flip_us =
-        frame_clock->last_flip_time_us -
+        flip_time_us -
         frame_info->cpu_time_before_buffer_swap_us;
 
       CLUTTER_NOTE (FRAME_TIMINGS,
-                    "update2dispatch %ld µs, dispatch2swap %ld µs, swap2render %ld µs, swap2flip %ld µs",
+                    "%s: update2dispatch %ld µs, dispatch2swap %ld µs, swap2render %ld µs, swap2flip %ld µs",
+                    debug_state,
                     frame_clock->last_dispatch_lateness_us,
                     dispatch_to_swap_us,
                     swap_to_rendering_done_us,
@@ -316,7 +356,8 @@ clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock,
     }
   else
     {
-      CLUTTER_NOTE (FRAME_TIMINGS, "update2dispatch %ld µs",
+      CLUTTER_NOTE (FRAME_TIMINGS, "%s: update2dispatch %ld µs",
+                    debug_state,
                     frame_clock->last_dispatch_lateness_us);
     }
 
@@ -347,11 +388,18 @@ clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock,
     case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
       g_warn_if_reached ();
       break;
-    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING:
-    case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
       frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_IDLE;
       maybe_reschedule_update (frame_clock);
       break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
+      maybe_reschedule_update (frame_clock);
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE;
+      maybe_reschedule_update (frame_clock);
+      break;
     }
 }
 
@@ -367,11 +415,18 @@ clutter_frame_clock_notify_ready (ClutterFrameClock *frame_clock)
     case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
       g_warn_if_reached ();
       break;
-    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING:
-    case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
       frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_IDLE;
       maybe_reschedule_update (frame_clock);
       break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
+      maybe_reschedule_update (frame_clock);
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE;
+      maybe_reschedule_update (frame_clock);
+      break;
     }
 }
 
@@ -423,8 +478,6 @@ clutter_frame_clock_compute_max_render_time_us (ClutterFrameClock *frame_clock)
     frame_clock->vblank_duration_us +
     clutter_max_render_time_constant_us;
 
-  max_render_time_us = CLAMP (max_render_time_us, 0, refresh_interval_us);
-
   return max_render_time_us;
 }
 
@@ -438,7 +491,7 @@ calculate_next_update_time_us (ClutterFrameClock *frame_clock,
   int64_t refresh_interval_us;
   int64_t min_render_time_allowed_us;
   int64_t max_render_time_allowed_us;
-  int64_t next_presentation_time_us;
+  int64_t next_presentation_time_us = 0;
   int64_t next_update_time_us;
 
   now_us = g_get_monotonic_time ();
@@ -482,7 +535,24 @@ calculate_next_update_time_us (ClutterFrameClock *frame_clock,
    *
    */
   last_presentation_time_us = frame_clock->last_presentation_time_us;
-  next_presentation_time_us = last_presentation_time_us + refresh_interval_us;
+  switch (frame_clock->state)
+    {
+    case CLUTTER_FRAME_CLOCK_STATE_INIT:
+    case CLUTTER_FRAME_CLOCK_STATE_IDLE:
+    case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+      next_presentation_time_us = last_presentation_time_us +
+                                  refresh_interval_us;
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+      next_presentation_time_us = last_presentation_time_us +
+                                  2 * refresh_interval_us;
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
+      next_presentation_time_us = last_presentation_time_us +
+                                  3 * refresh_interval_us;
+      break;
+    }
 
   /*
    * However, the last presentation could have happened more than a frame ago.
@@ -596,8 +666,12 @@ clutter_frame_clock_inhibit (ClutterFrameClock *frame_clock)
           frame_clock->pending_reschedule = TRUE;
           frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_IDLE;
           break;
-        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING:
-        case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED:
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+          frame_clock->pending_reschedule = TRUE;
+          frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE;
+          break;
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
           break;
         }
 
@@ -633,11 +707,17 @@ clutter_frame_clock_schedule_update_now (ClutterFrameClock *frame_clock)
     case CLUTTER_FRAME_CLOCK_STATE_INIT:
     case CLUTTER_FRAME_CLOCK_STATE_IDLE:
       next_update_time_us = g_get_monotonic_time ();
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
       break;
     case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
       return;
-    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING:
-    case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
+      next_update_time_us = g_get_monotonic_time ();
+      frame_clock->state =
+        CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED;
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
       frame_clock->pending_reschedule = TRUE;
       frame_clock->pending_reschedule_now = TRUE;
       return;
@@ -647,7 +727,6 @@ clutter_frame_clock_schedule_update_now (ClutterFrameClock *frame_clock)
 
   frame_clock->next_update_time_us = next_update_time_us;
   g_source_set_ready_time (frame_clock->source, next_update_time_us);
-  frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
   frame_clock->is_next_presentation_time_valid = FALSE;
 }
 
@@ -655,6 +734,10 @@ void
 clutter_frame_clock_schedule_update (ClutterFrameClock *frame_clock)
 {
   int64_t next_update_time_us = -1;
+  TripleBufferingMode current_mode = triple_buffering_mode;
+
+  if (frame_clock->last_flip_hints & CLUTTER_FRAME_HINT_DIRECT_SCANOUT_ATTEMPTED)
+    current_mode = TRIPLE_BUFFERING_MODE_NEVER;
 
   if (frame_clock->inhibit_count > 0)
     {
@@ -666,6 +749,7 @@ clutter_frame_clock_schedule_update (ClutterFrameClock *frame_clock)
     {
     case CLUTTER_FRAME_CLOCK_STATE_INIT:
       next_update_time_us = g_get_monotonic_time ();
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
       break;
     case CLUTTER_FRAME_CLOCK_STATE_IDLE:
       calculate_next_update_time_us (frame_clock,
@@ -673,11 +757,36 @@ clutter_frame_clock_schedule_update (ClutterFrameClock *frame_clock)
                                      &frame_clock->next_presentation_time_us);
       frame_clock->is_next_presentation_time_valid =
         (frame_clock->next_presentation_time_us != 0);
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
       break;
     case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
       return;
-    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING:
-    case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
+      switch (current_mode)
+        {
+        case TRIPLE_BUFFERING_MODE_NEVER:
+          frame_clock->pending_reschedule = TRUE;
+          return;
+        case TRIPLE_BUFFERING_MODE_AUTO:
+          calculate_next_update_time_us (frame_clock,
+                                         &next_update_time_us,
+                                         &frame_clock->next_presentation_time_us);
+          frame_clock->is_next_presentation_time_valid =
+            (frame_clock->next_presentation_time_us != 0);
+          frame_clock->state =
+            CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED;
+          break;
+        case TRIPLE_BUFFERING_MODE_ALWAYS:
+          next_update_time_us = g_get_monotonic_time ();
+          frame_clock->next_presentation_time_us = 0;
+          frame_clock->is_next_presentation_time_valid = FALSE;
+          frame_clock->state =
+            CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED;
+          break;
+        }
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
       frame_clock->pending_reschedule = TRUE;
       return;
     }
@@ -686,7 +795,6 @@ clutter_frame_clock_schedule_update (ClutterFrameClock *frame_clock)
 
   frame_clock->next_update_time_us = next_update_time_us;
   g_source_set_ready_time (frame_clock->source, next_update_time_us);
-  frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
 }
 
 static void
@@ -717,7 +825,7 @@ clutter_frame_clock_dispatch (ClutterFrameClock *frame_clock,
                              frame_clock->refresh_interval_us;
 
   lateness_us = time_us - ideal_dispatch_time_us;
-  if (lateness_us < 0 || lateness_us >= frame_clock->refresh_interval_us)
+  if (lateness_us < 0 || lateness_us >= frame_clock->refresh_interval_us / 4)
     frame_clock->last_dispatch_lateness_us = 0;
   else
     frame_clock->last_dispatch_lateness_us = lateness_us;
@@ -726,10 +834,25 @@ clutter_frame_clock_dispatch (ClutterFrameClock *frame_clock,
     MAX (frame_clock->shortterm.max_dispatch_lateness_us,
          frame_clock->last_dispatch_lateness_us);
 
+  frame_clock->prev_last_dispatch_time_us = frame_clock->last_dispatch_time_us;
   frame_clock->last_dispatch_time_us = time_us;
   g_source_set_ready_time (frame_clock->source, -1);
 
-  frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHING;
+  switch (frame_clock->state)
+    {
+    case CLUTTER_FRAME_CLOCK_STATE_INIT:
+    case CLUTTER_FRAME_CLOCK_STATE_IDLE:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
+      g_warn_if_reached ();
+      return;
+    case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE;
+      break;
+    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+      frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO;
+      break;
+    }
 
   frame_count = frame_clock->frame_count++;
 
@@ -753,25 +876,31 @@ clutter_frame_clock_dispatch (ClutterFrameClock *frame_clock,
   result = iface->frame (frame_clock, frame, frame_clock->listener.user_data);
   COGL_TRACE_END (ClutterFrameClockFrame);
 
-  switch (frame_clock->state)
+  switch (result)
     {
-    case CLUTTER_FRAME_CLOCK_STATE_INIT:
-    case CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED:
-      g_warn_if_reached ();
-      break;
-    case CLUTTER_FRAME_CLOCK_STATE_IDLE:
-    case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+    case CLUTTER_FRAME_RESULT_PENDING_PRESENTED:
       break;
-    case CLUTTER_FRAME_CLOCK_STATE_DISPATCHING:
-      switch (result)
+    case CLUTTER_FRAME_RESULT_IDLE:
+      /* The frame was aborted; nothing to paint/present */
+      switch (frame_clock->state)
         {
-        case CLUTTER_FRAME_RESULT_PENDING_PRESENTED:
-          frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_PENDING_PRESENTED;
+        case CLUTTER_FRAME_CLOCK_STATE_INIT:
+        case CLUTTER_FRAME_CLOCK_STATE_IDLE:
+        case CLUTTER_FRAME_CLOCK_STATE_SCHEDULED:
+          g_warn_if_reached ();
           break;
-        case CLUTTER_FRAME_RESULT_IDLE:
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE:
           frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_IDLE;
           maybe_reschedule_update (frame_clock);
           break;
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE_AND_SCHEDULED:
+          frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_SCHEDULED;
+          maybe_reschedule_update (frame_clock);
+          break;
+        case CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_TWO:
+          frame_clock->state = CLUTTER_FRAME_CLOCK_STATE_DISPATCHED_ONE;
+          maybe_reschedule_update (frame_clock);
+          break;
         }
       break;
     }
@@ -804,10 +933,13 @@ frame_clock_source_dispatch (GSource     *source,
 }
 
 void
-clutter_frame_clock_record_flip_time (ClutterFrameClock *frame_clock,
-                                      int64_t            flip_time_us)
+clutter_frame_clock_record_flip (ClutterFrameClock *frame_clock,
+                                 int64_t            flip_time_us,
+                                 ClutterFrameHint   hints)
 {
+  frame_clock->prev_last_flip_time_us = frame_clock->last_flip_time_us;
   frame_clock->last_flip_time_us = flip_time_us;
+  frame_clock->last_flip_hints = hints;
 }
 
 GString *
@@ -939,6 +1071,15 @@ static void
 clutter_frame_clock_class_init (ClutterFrameClockClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  const char *mode_str;
+
+  mode_str = g_getenv ("MUTTER_DEBUG_TRIPLE_BUFFERING");
+  if (!g_strcmp0 (mode_str, "never"))
+    triple_buffering_mode = TRIPLE_BUFFERING_MODE_NEVER;
+  else if (!g_strcmp0 (mode_str, "auto"))
+    triple_buffering_mode = TRIPLE_BUFFERING_MODE_AUTO;
+  else if (!g_strcmp0 (mode_str, "always"))
+    triple_buffering_mode = TRIPLE_BUFFERING_MODE_ALWAYS;
 
   object_class->dispose = clutter_frame_clock_dispose;
 
diff --git a/clutter/clutter/clutter-frame-clock.h b/clutter/clutter/clutter-frame-clock.h
index 9dfc8dc..cfb7ffb 100644
--- a/clutter/clutter/clutter-frame-clock.h
+++ b/clutter/clutter/clutter-frame-clock.h
@@ -34,6 +34,12 @@ typedef enum _ClutterFrameResult
   CLUTTER_FRAME_RESULT_IDLE,
 } ClutterFrameResult;
 
+typedef enum _ClutterFrameHint
+{
+  CLUTTER_FRAME_HINT_NONE = 0,
+  CLUTTER_FRAME_HINT_DIRECT_SCANOUT_ATTEMPTED = 1 << 0,
+} ClutterFrameHint;
+
 #define CLUTTER_TYPE_FRAME_CLOCK (clutter_frame_clock_get_type ())
 CLUTTER_EXPORT
 G_DECLARE_FINAL_TYPE (ClutterFrameClock, clutter_frame_clock,
@@ -90,8 +96,9 @@ void clutter_frame_clock_remove_timeline (ClutterFrameClock *frame_clock,
 CLUTTER_EXPORT
 float clutter_frame_clock_get_refresh_rate (ClutterFrameClock *frame_clock);
 
-void clutter_frame_clock_record_flip_time (ClutterFrameClock *frame_clock,
-                                           int64_t            flip_time_us);
+void clutter_frame_clock_record_flip (ClutterFrameClock *frame_clock,
+                                      int64_t            flip_time_us,
+                                      ClutterFrameHint   hints);
 
 GString * clutter_frame_clock_get_max_render_time_debug_info (ClutterFrameClock *frame_clock);
 
diff --git a/clutter/clutter/clutter-frame-private.h b/clutter/clutter/clutter-frame-private.h
index 51a837f..db3cb0d 100644
--- a/clutter/clutter/clutter-frame-private.h
+++ b/clutter/clutter/clutter-frame-private.h
@@ -31,6 +31,7 @@ struct _ClutterFrame
 
   gboolean has_result;
   ClutterFrameResult result;
+  ClutterFrameHint hints;
 };
 
 CLUTTER_EXPORT
diff --git a/clutter/clutter/clutter-frame.c b/clutter/clutter/clutter-frame.c
index 259cf70..3a34ed7 100644
--- a/clutter/clutter/clutter-frame.c
+++ b/clutter/clutter/clutter-frame.c
@@ -90,3 +90,16 @@ clutter_frame_set_result (ClutterFrame       *frame,
   frame->result = result;
   frame->has_result = TRUE;
 }
+
+void
+clutter_frame_set_hint (ClutterFrame     *frame,
+                        ClutterFrameHint  hint)
+{
+  frame->hints |= hint;
+}
+
+ClutterFrameHint
+clutter_frame_get_hints (ClutterFrame *frame)
+{
+  return frame->hints;
+}
diff --git a/clutter/clutter/clutter-frame.h b/clutter/clutter/clutter-frame.h
index 1837816..8df7fdf 100644
--- a/clutter/clutter/clutter-frame.h
+++ b/clutter/clutter/clutter-frame.h
@@ -51,6 +51,13 @@ void clutter_frame_set_result (ClutterFrame       *frame,
 CLUTTER_EXPORT
 gboolean clutter_frame_has_result (ClutterFrame *frame);
 
+CLUTTER_EXPORT
+void clutter_frame_set_hint (ClutterFrame     *frame,
+                             ClutterFrameHint  hint);
+
+CLUTTER_EXPORT
+ClutterFrameHint clutter_frame_get_hints (ClutterFrame *frame);
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (ClutterFrame, clutter_frame_unref)
 
 #endif /* CLUTTER_FRAME_H */
diff --git a/clutter/clutter/clutter-stage-view.c b/clutter/clutter/clutter-stage-view.c
index 06b289a..740b2ea 100644
--- a/clutter/clutter/clutter-stage-view.c
+++ b/clutter/clutter/clutter-stage-view.c
@@ -1249,8 +1249,9 @@ handle_frame_clock_frame (ClutterFrameClock *frame_clock,
 
       _clutter_stage_window_redraw_view (stage_window, view, frame);
 
-      clutter_frame_clock_record_flip_time (frame_clock,
-                                            g_get_monotonic_time ());
+      clutter_frame_clock_record_flip (frame_clock,
+                                       g_get_monotonic_time (),
+                                       clutter_frame_get_hints (frame));
 
       clutter_stage_emit_after_paint (stage, view, frame);
 
diff --git a/cogl/cogl/cogl-onscreen-private.h b/cogl/cogl/cogl-onscreen-private.h
index dffe018..e0215f7 100644
--- a/cogl/cogl/cogl-onscreen-private.h
+++ b/cogl/cogl/cogl-onscreen-private.h
@@ -97,4 +97,7 @@ cogl_onscreen_peek_tail_frame_info (CoglOnscreen *onscreen);
 COGL_EXPORT CoglFrameInfo *
 cogl_onscreen_pop_head_frame_info (CoglOnscreen *onscreen);
 
+COGL_EXPORT unsigned int
+cogl_onscreen_count_pending_frames (CoglOnscreen *onscreen);
+
 #endif /* __COGL_ONSCREEN_PRIVATE_H */
diff --git a/cogl/cogl/cogl-onscreen.c b/cogl/cogl/cogl-onscreen.c
index 842ecec..1e2b11d 100644
--- a/cogl/cogl/cogl-onscreen.c
+++ b/cogl/cogl/cogl-onscreen.c
@@ -508,6 +508,14 @@ cogl_onscreen_pop_head_frame_info (CoglOnscreen *onscreen)
   return g_queue_pop_head (&priv->pending_frame_infos);
 }
 
+unsigned int
+cogl_onscreen_count_pending_frames (CoglOnscreen *onscreen)
+{
+  CoglOnscreenPrivate *priv = cogl_onscreen_get_instance_private (onscreen);
+
+  return g_queue_get_length (&priv->pending_frame_infos);
+}
+
 CoglFrameClosure *
 cogl_onscreen_add_frame_callback (CoglOnscreen *onscreen,
                                   CoglFrameCallback callback,
diff --git a/src/backends/meta-stage-impl.c b/src/backends/meta-stage-impl.c
index 7774393..acf4437 100644
--- a/src/backends/meta-stage-impl.c
+++ b/src/backends/meta-stage-impl.c
@@ -730,6 +730,8 @@ meta_stage_impl_redraw_view (ClutterStageWindow *stage_window,
     {
       g_autoptr (GError) error = NULL;
 
+      clutter_frame_set_hint (frame, CLUTTER_FRAME_HINT_DIRECT_SCANOUT_ATTEMPTED);
+
       if (meta_stage_impl_scanout_view (stage_impl,
                                         stage_view,
                                         scanout,
diff --git a/src/backends/native/meta-cursor-renderer-native.c b/src/backends/native/meta-cursor-renderer-native.c
index 5777434..ca8774b 100644
--- a/src/backends/native/meta-cursor-renderer-native.c
+++ b/src/backends/native/meta-cursor-renderer-native.c
@@ -58,19 +58,6 @@
 #include "wayland/meta-wayland-buffer.h"
 #endif
 
-/* When animating a cursor, we usually call drmModeSetCursor2 once per frame.
- * Though, testing shows that we need to triple buffer the cursor buffer in
- * order to avoid glitches when animating the cursor, at least when running on
- * Intel. The reason for this might be (but is not confirmed to be) due to
- * the user space gbm_bo cache, making us reuse and overwrite the kernel side
- * buffer content before it was scanned out. To avoid this, we keep a user space
- * reference to each buffer we set until at least one frame after it was drawn.
- * In effect, this means we three active cursor gbm_bo's: one that that just has
- * been set, one that was previously set and may or may not have been scanned
- * out, and one pending that will be replaced if the cursor sprite changes.
- */
-#define HW_CURSOR_BUFFER_COUNT 3
-
 static GQuark quark_cursor_sprite = 0;
 
 typedef struct _CrtcCursorData
@@ -104,19 +91,10 @@ typedef struct _MetaCursorRendererNativeGpuData
   uint64_t cursor_height;
 } MetaCursorRendererNativeGpuData;
 
-typedef enum _MetaCursorBufferState
-{
-  META_CURSOR_BUFFER_STATE_NONE,
-  META_CURSOR_BUFFER_STATE_SET,
-  META_CURSOR_BUFFER_STATE_INVALIDATED,
-} MetaCursorBufferState;
-
 typedef struct _MetaCursorNativeGpuState
 {
   MetaGpu *gpu;
-  unsigned int active_buffer_idx;
-  MetaCursorBufferState pending_buffer_state;
-  MetaDrmBuffer *buffers[HW_CURSOR_BUFFER_COUNT];
+  MetaDrmBuffer *buffer;
 } MetaCursorNativeGpuState;
 
 typedef struct _MetaCursorNativePrivate
@@ -197,44 +175,17 @@ meta_cursor_renderer_native_finalize (GObject *object)
   G_OBJECT_CLASS (meta_cursor_renderer_native_parent_class)->finalize (object);
 }
 
-static unsigned int
-get_pending_cursor_sprite_buffer_index (MetaCursorNativeGpuState *cursor_gpu_state)
-{
-  return (cursor_gpu_state->active_buffer_idx + 1) % HW_CURSOR_BUFFER_COUNT;
-}
-
-static MetaDrmBuffer *
-get_pending_cursor_sprite_buffer (MetaCursorNativeGpuState *cursor_gpu_state)
-{
-  unsigned int pending_buffer_idx;
-
-  pending_buffer_idx =
-    get_pending_cursor_sprite_buffer_index (cursor_gpu_state);
-  return cursor_gpu_state->buffers[pending_buffer_idx];
-}
-
-static MetaDrmBuffer *
-get_active_cursor_sprite_buffer (MetaCursorNativeGpuState *cursor_gpu_state)
-{
-  return cursor_gpu_state->buffers[cursor_gpu_state->active_buffer_idx];
-}
-
 static void
-set_pending_cursor_sprite_buffer (MetaCursorSprite *cursor_sprite,
-                                  MetaGpuKms       *gpu_kms,
-                                  MetaDrmBuffer    *buffer)
+set_cursor_sprite_buffer (MetaCursorSprite *cursor_sprite,
+                          MetaGpuKms       *gpu_kms,
+                          MetaDrmBuffer    *buffer)
 {
   MetaCursorNativePrivate *cursor_priv;
   MetaCursorNativeGpuState *cursor_gpu_state;
-  unsigned int pending_buffer_idx;
 
   cursor_priv = ensure_cursor_priv (cursor_sprite);
   cursor_gpu_state = ensure_cursor_gpu_state (cursor_priv, gpu_kms);
-
-  pending_buffer_idx =
-    get_pending_cursor_sprite_buffer_index (cursor_gpu_state);
-  cursor_gpu_state->buffers[pending_buffer_idx] = buffer;
-  cursor_gpu_state->pending_buffer_state = META_CURSOR_BUFFER_STATE_SET;
+  cursor_gpu_state->buffer = buffer;
 }
 
 static void
@@ -309,10 +260,7 @@ assign_cursor_plane (MetaCursorRendererNative *native,
   MetaKmsUpdate *kms_update;
   MetaKmsPlaneAssignment *plane_assignment;
 
-  if (cursor_gpu_state->pending_buffer_state == META_CURSOR_BUFFER_STATE_SET)
-    buffer = get_pending_cursor_sprite_buffer (cursor_gpu_state);
-  else
-    buffer = get_active_cursor_sprite_buffer (cursor_gpu_state);
+  buffer = cursor_gpu_state->buffer;
 
   kms_crtc = meta_crtc_kms_get_kms_crtc (crtc_kms);
   kms_device = meta_kms_crtc_get_device (kms_crtc);
@@ -341,8 +289,8 @@ assign_cursor_plane (MetaCursorRendererNative *native,
     flags |= META_KMS_ASSIGN_PLANE_FLAG_FB_UNCHANGED;
 
   kms_update =
-    meta_kms_ensure_pending_update (meta_kms_device_get_kms (kms_device),
-                                    meta_kms_crtc_get_device (kms_crtc));
+    meta_kms_ensure_pending_update_for_crtc (meta_kms_device_get_kms (kms_device),
+                                             kms_crtc);
   plane_assignment = meta_kms_update_assign_plane (kms_update,
                                                    kms_crtc,
                                                    cursor_plane,
@@ -363,13 +311,6 @@ assign_cursor_plane (MetaCursorRendererNative *native,
                                        native);
 
   crtc_cursor_data->buffer = buffer;
-
-  if (cursor_gpu_state->pending_buffer_state == META_CURSOR_BUFFER_STATE_SET)
-    {
-      cursor_gpu_state->active_buffer_idx =
-        (cursor_gpu_state->active_buffer_idx + 1) % HW_CURSOR_BUFFER_COUNT;
-      cursor_gpu_state->pending_buffer_state = META_CURSOR_BUFFER_STATE_NONE;
-    }
 }
 
 static float
@@ -498,7 +439,7 @@ unset_crtc_cursor (MetaCursorRendererNative *native,
       MetaKms *kms = meta_kms_device_get_kms (kms_device);
       MetaKmsUpdate *kms_update;
 
-      kms_update = meta_kms_ensure_pending_update (kms, kms_device);
+      kms_update = meta_kms_ensure_pending_update_for_crtc (kms, kms_crtc);
       meta_kms_update_unassign_plane (kms_update, kms_crtc, cursor_plane);
     }
 
@@ -606,19 +547,7 @@ has_valid_cursor_sprite_buffer (MetaCursorSprite *cursor_sprite,
   if (!cursor_gpu_state)
     return FALSE;
 
-  switch (cursor_gpu_state->pending_buffer_state)
-    {
-    case META_CURSOR_BUFFER_STATE_NONE:
-      return get_active_cursor_sprite_buffer (cursor_gpu_state) != NULL;
-    case META_CURSOR_BUFFER_STATE_SET:
-      return TRUE;
-    case META_CURSOR_BUFFER_STATE_INVALIDATED:
-      return FALSE;
-    }
-
-  g_assert_not_reached ();
-
-  return FALSE;
+  return cursor_gpu_state->buffer != NULL;
 }
 
 static void
@@ -1125,16 +1054,14 @@ unset_crtc_cursor_renderer_privates (MetaGpu       *gpu,
 static void
 cursor_gpu_state_free (MetaCursorNativeGpuState *cursor_gpu_state)
 {
-  int i;
   MetaDrmBuffer *active_buffer;
 
-  active_buffer = get_active_cursor_sprite_buffer (cursor_gpu_state);
+  active_buffer = cursor_gpu_state->buffer;
   if (active_buffer)
     unset_crtc_cursor_renderer_privates (cursor_gpu_state->gpu,
                                          active_buffer);
 
-  for (i = 0; i < HW_CURSOR_BUFFER_COUNT; i++)
-    g_clear_object (&cursor_gpu_state->buffers[i]);
+  g_clear_object (&cursor_gpu_state->buffer);
   g_free (cursor_gpu_state);
 }
 
@@ -1171,14 +1098,7 @@ invalidate_cursor_gpu_state (MetaCursorSprite *cursor_sprite)
 
   g_hash_table_iter_init (&iter, cursor_priv->gpu_states);
   while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &cursor_gpu_state))
-    {
-      unsigned int pending_buffer_idx;
-
-      pending_buffer_idx = get_pending_cursor_sprite_buffer_index (cursor_gpu_state);
-      g_clear_object (&cursor_gpu_state->buffers[pending_buffer_idx]);
-      cursor_gpu_state->pending_buffer_state =
-        META_CURSOR_BUFFER_STATE_INVALIDATED;
-    }
+    g_clear_object (&cursor_gpu_state->buffer);
 }
 
 static void
@@ -1416,35 +1336,7 @@ load_cursor_sprite_gbm_buffer_for_gpu (MetaCursorRendererNative *native,
       return;
     }
 
-  set_pending_cursor_sprite_buffer (cursor_sprite, gpu_kms, buffer);
-}
-
-static gboolean
-is_cursor_hw_state_valid (MetaCursorSprite *cursor_sprite,
-                          MetaGpuKms       *gpu_kms)
-{
-  MetaCursorNativePrivate *cursor_priv;
-  MetaCursorNativeGpuState *cursor_gpu_state;
-
-  cursor_priv = get_cursor_priv (cursor_sprite);
-  if (!cursor_priv)
-    return FALSE;
-
-  cursor_gpu_state = get_cursor_gpu_state (cursor_priv, gpu_kms);
-  if (!cursor_gpu_state)
-    return FALSE;
-
-  switch (cursor_gpu_state->pending_buffer_state)
-    {
-    case META_CURSOR_BUFFER_STATE_SET:
-    case META_CURSOR_BUFFER_STATE_NONE:
-      return TRUE;
-    case META_CURSOR_BUFFER_STATE_INVALIDATED:
-      return FALSE;
-    }
-
-  g_assert_not_reached ();
-  return FALSE;
+  set_cursor_sprite_buffer (cursor_sprite, gpu_kms, buffer);
 }
 
 static gboolean
@@ -1631,7 +1523,7 @@ realize_cursor_sprite_from_wl_buffer_for_gpu (MetaCursorRenderer      *renderer,
   if (!cursor_renderer_gpu_data || cursor_renderer_gpu_data->hw_cursor_broken)
     return;
 
-  if (is_cursor_hw_state_valid (cursor_sprite, gpu_kms) &&
+  if (has_valid_cursor_sprite_buffer (cursor_sprite, gpu_kms) &&
       is_cursor_scale_and_transform_valid (renderer, cursor_sprite))
     return;
 
@@ -1776,8 +1668,8 @@ realize_cursor_sprite_from_wl_buffer_for_gpu (MetaCursorRenderer      *renderer,
           return;
         }
 
-      set_pending_cursor_sprite_buffer (cursor_sprite, gpu_kms,
-                                        META_DRM_BUFFER (buffer_gbm));
+      set_cursor_sprite_buffer (cursor_sprite, gpu_kms,
+                                META_DRM_BUFFER (buffer_gbm));
     }
 }
 #endif
@@ -1801,7 +1693,7 @@ realize_cursor_sprite_from_xcursor_for_gpu (MetaCursorRenderer      *renderer,
   if (!cursor_renderer_gpu_data || cursor_renderer_gpu_data->hw_cursor_broken)
     return;
 
-  if (is_cursor_hw_state_valid (cursor_sprite, gpu_kms) &&
+  if (has_valid_cursor_sprite_buffer (cursor_sprite, gpu_kms) &&
       is_cursor_scale_and_transform_valid (renderer, cursor_sprite))
     return;
 
diff --git a/src/backends/native/meta-kms-crtc.c b/src/backends/native/meta-kms-crtc.c
index 31e8be0..18f42b3 100644
--- a/src/backends/native/meta-kms-crtc.c
+++ b/src/backends/native/meta-kms-crtc.c
@@ -44,6 +44,8 @@ struct _MetaKmsCrtc
   MetaKmsCrtcState current_state;
 
   MetaKmsCrtcPropTable prop_table;
+
+  MetaSwapChain *swap_chain;
 };
 
 G_DEFINE_TYPE (MetaKmsCrtc, meta_kms_crtc, G_TYPE_OBJECT)
@@ -95,6 +97,12 @@ meta_kms_crtc_get_prop_drm_value (MetaKmsCrtc     *crtc,
   return meta_kms_prop_convert_value (prop, value);
 }
 
+MetaSwapChain *
+meta_kms_crtc_get_swap_chain (MetaKmsCrtc *crtc)
+{
+  return crtc->swap_chain;
+}
+
 gboolean
 meta_kms_crtc_is_active (MetaKmsCrtc *crtc)
 {
@@ -410,12 +418,23 @@ meta_kms_crtc_new (MetaKmsImplDevice  *impl_device,
   return crtc;
 }
 
+static void
+meta_kms_crtc_dispose (GObject *object)
+{
+  MetaKmsCrtc *crtc = META_KMS_CRTC (object);
+
+  meta_swap_chain_release_buffers (crtc->swap_chain);
+
+  G_OBJECT_CLASS (meta_kms_crtc_parent_class)->dispose (object);
+}
+
 static void
 meta_kms_crtc_finalize (GObject *object)
 {
   MetaKmsCrtc *crtc = META_KMS_CRTC (object);
 
   clear_gamma_state (&crtc->current_state);
+  g_clear_object (&crtc->swap_chain);
 
   G_OBJECT_CLASS (meta_kms_crtc_parent_class)->finalize (object);
 }
@@ -424,6 +443,7 @@ static void
 meta_kms_crtc_init (MetaKmsCrtc *crtc)
 {
   crtc->current_state.gamma.size = 0;
+  crtc->swap_chain = meta_swap_chain_new ();
 }
 
 static void
@@ -431,5 +451,6 @@ meta_kms_crtc_class_init (MetaKmsCrtcClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+  object_class->dispose = meta_kms_crtc_dispose;
   object_class->finalize = meta_kms_crtc_finalize;
 }
diff --git a/src/backends/native/meta-kms-crtc.h b/src/backends/native/meta-kms-crtc.h
index 54801dd..13c843c 100644
--- a/src/backends/native/meta-kms-crtc.h
+++ b/src/backends/native/meta-kms-crtc.h
@@ -25,6 +25,7 @@
 #include <xf86drmMode.h>
 
 #include "backends/native/meta-kms-types.h"
+#include "backends/native/meta-swap-chain.h"
 #include "core/util-private.h"
 #include "meta/boxes.h"
 
@@ -84,4 +85,6 @@ MetaKmsCrtcGamma * meta_kms_crtc_gamma_new (MetaKmsCrtc    *crtc,
                                             const uint16_t *green,
                                             const uint16_t *blue);
 
+MetaSwapChain * meta_kms_crtc_get_swap_chain (MetaKmsCrtc *crtc);
+
 #endif /* META_KMS_CRTC_H */
diff --git a/src/backends/native/meta-kms-impl-device-atomic.c b/src/backends/native/meta-kms-impl-device-atomic.c
index e938e45..dcab3e1 100644
--- a/src/backends/native/meta-kms-impl-device-atomic.c
+++ b/src/backends/native/meta-kms-impl-device-atomic.c
@@ -457,6 +457,7 @@ process_plane_assignment (MetaKmsImplDevice  *impl_device,
 {
   MetaKmsPlaneAssignment *plane_assignment = update_entry;
   MetaKmsPlane *plane = plane_assignment->plane;
+  MetaKmsUpdateFlag flags = (MetaKmsUpdateFlag) user_data;
   MetaDrmBuffer *buffer;
   MetaKmsFbDamage *fb_damage;
   uint32_t prop_id;
@@ -609,6 +610,12 @@ process_plane_assignment (MetaKmsImplDevice  *impl_device,
                                error))
         return FALSE;
     }
+
+  if (!(flags & META_KMS_UPDATE_FLAG_TEST_ONLY))
+    meta_swap_chain_push_buffer (meta_kms_crtc_get_swap_chain (plane_assignment->crtc),
+                                 meta_kms_plane_get_id (plane),
+                                 G_OBJECT (buffer));
+
   return TRUE;
 }
 
@@ -986,7 +993,7 @@ meta_kms_impl_device_atomic_process_update (MetaKmsImplDevice *impl_device,
                         req,
                         blob_ids,
                         meta_kms_update_get_plane_assignments (update),
-                        NULL,
+                        GUINT_TO_POINTER (flags),
                         process_plane_assignment,
                         &error))
     goto err;
diff --git a/src/backends/native/meta-kms-impl-device-simple.c b/src/backends/native/meta-kms-impl-device-simple.c
index 648de51..758d2aa 100644
--- a/src/backends/native/meta-kms-impl-device-simple.c
+++ b/src/backends/native/meta-kms-impl-device-simple.c
@@ -486,6 +486,8 @@ process_mode_set (MetaKmsImplDevice  *impl_device,
       return FALSE;
     }
 
+  meta_swap_chain_swap_buffers (meta_kms_crtc_get_swap_chain (crtc));
+
   if (drm_mode)
     {
       g_hash_table_replace (impl_device_simple->cached_mode_sets,
@@ -550,7 +552,7 @@ is_timestamp_earlier_than (uint64_t ts1,
 typedef struct _RetryPageFlipData
 {
   MetaKmsCrtc *crtc;
-  uint32_t fb_id;
+  MetaDrmBuffer *fb;
   MetaKmsPageFlipData *page_flip_data;
   float refresh_rate;
   uint64_t retry_time_us;
@@ -563,6 +565,7 @@ retry_page_flip_data_free (RetryPageFlipData *retry_page_flip_data)
   g_assert (!retry_page_flip_data->page_flip_data);
   g_clear_pointer (&retry_page_flip_data->custom_page_flip,
                    meta_kms_custom_page_flip_free);
+  g_clear_object (&retry_page_flip_data->fb);
   g_free (retry_page_flip_data);
 }
 
@@ -630,16 +633,21 @@ retry_page_flips (gpointer user_data)
         }
       else
         {
+          uint32_t fb_id =
+            retry_page_flip_data->fb ?
+            meta_drm_buffer_get_fb_id (retry_page_flip_data->fb) :
+            0;
+
           meta_topic (META_DEBUG_KMS,
                       "[simple] Retrying page flip on CRTC %u (%s) with %u",
                       meta_kms_crtc_get_id (crtc),
                       meta_kms_impl_device_get_path (impl_device),
-                      retry_page_flip_data->fb_id);
+                      fb_id);
 
           fd = meta_kms_impl_device_get_fd (impl_device);
           ret = drmModePageFlip (fd,
                                  meta_kms_crtc_get_id (crtc),
-                                 retry_page_flip_data->fb_id,
+                                 fb_id,
                                  DRM_MODE_PAGE_FLIP_EVENT,
                                  retry_page_flip_data->page_flip_data);
         }
@@ -726,7 +734,7 @@ retry_page_flips (gpointer user_data)
 static void
 schedule_retry_page_flip (MetaKmsImplDeviceSimple *impl_device_simple,
                           MetaKmsCrtc             *crtc,
-                          uint32_t                 fb_id,
+                          MetaDrmBuffer           *fb,
                           float                    refresh_rate,
                           MetaKmsPageFlipData     *page_flip_data,
                           MetaKmsCustomPageFlip   *custom_page_flip)
@@ -741,7 +749,7 @@ schedule_retry_page_flip (MetaKmsImplDeviceSimple *impl_device_simple,
   retry_page_flip_data = g_new0 (RetryPageFlipData, 1);
   *retry_page_flip_data = (RetryPageFlipData) {
     .crtc = crtc,
-    .fb_id = fb_id,
+    .fb = fb ? g_object_ref (fb) : NULL,
     .page_flip_data = page_flip_data,
     .refresh_rate = refresh_rate,
     .retry_time_us = retry_time_us,
@@ -875,6 +883,8 @@ mode_set_fallback (MetaKmsImplDeviceSimple  *impl_device_simple,
       return FALSE;
     }
 
+  meta_swap_chain_swap_buffers (meta_kms_crtc_get_swap_chain (crtc));
+
   if (!impl_device_simple->mode_set_fallback_feedback_source)
     {
       GSource *source;
@@ -999,20 +1009,20 @@ dispatch_page_flip (MetaKmsImplDevice    *impl_device,
       cached_mode_set = get_cached_mode_set (impl_device_simple, crtc);
       if (cached_mode_set)
         {
-          uint32_t fb_id;
+          MetaDrmBuffer *fb;
           drmModeModeInfo *drm_mode;
           float refresh_rate;
 
           if (plane_assignment)
-            fb_id = meta_drm_buffer_get_fb_id (plane_assignment->buffer);
+            fb = plane_assignment->buffer;
           else
-            fb_id = 0;
+            fb = NULL;
           drm_mode = cached_mode_set->drm_mode;
           refresh_rate = meta_calculate_drm_mode_refresh_rate (drm_mode);
           meta_kms_impl_device_hold_fd (impl_device);
           schedule_retry_page_flip (impl_device_simple,
                                     crtc,
-                                    fb_id,
+                                    fb,
                                     refresh_rate,
                                     page_flip_data,
                                     g_steal_pointer (&custom_page_flip));
@@ -1302,7 +1312,7 @@ process_plane_assignment (MetaKmsImplDevice       *impl_device,
     {
     case META_KMS_PLANE_TYPE_PRIMARY:
       /* Handled as part of the mode-set and page flip. */
-      return TRUE;
+      goto assigned;
     case META_KMS_PLANE_TYPE_CURSOR:
       if (!process_cursor_plane_assignment (impl_device, update,
                                             plane_assignment,
@@ -1316,7 +1326,7 @@ process_plane_assignment (MetaKmsImplDevice       *impl_device,
         }
       else
         {
-          return TRUE;
+          goto assigned;
         }
     case META_KMS_PLANE_TYPE_OVERLAY:
       error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_FAILED,
@@ -1329,6 +1339,12 @@ process_plane_assignment (MetaKmsImplDevice       *impl_device,
     }
 
   g_assert_not_reached ();
+
+assigned:
+  meta_swap_chain_push_buffer (meta_kms_crtc_get_swap_chain (plane_assignment->crtc),
+                               meta_kms_plane_get_id (plane),
+                               G_OBJECT (plane_assignment->buffer));
+  return TRUE;
 }
 
 static gboolean
diff --git a/src/backends/native/meta-kms-impl-device.c b/src/backends/native/meta-kms-impl-device.c
index d9ea276..c722280 100644
--- a/src/backends/native/meta-kms-impl-device.c
+++ b/src/backends/native/meta-kms-impl-device.c
@@ -1201,11 +1201,25 @@ meta_kms_impl_device_init_mode_setting (MetaKmsImplDevice  *impl_device,
   return TRUE;
 }
 
+static void
+release_buffers (gpointer data,
+                 gpointer user_data)
+{
+  MetaKmsCrtc *crtc = data;
+  MetaSwapChain *swap_chain = meta_kms_crtc_get_swap_chain (crtc);
+
+  meta_swap_chain_release_buffers (swap_chain);
+}
+
 void
 meta_kms_impl_device_prepare_shutdown (MetaKmsImplDevice *impl_device)
 {
+  MetaKmsImplDevicePrivate *priv =
+    meta_kms_impl_device_get_instance_private (impl_device);
   MetaKmsImplDeviceClass *klass = META_KMS_IMPL_DEVICE_GET_CLASS (impl_device);
 
+  g_list_foreach (priv->crtcs, release_buffers, NULL);
+
   if (klass->prepare_shutdown)
     klass->prepare_shutdown (impl_device);
 
diff --git a/src/backends/native/meta-kms-page-flip.c b/src/backends/native/meta-kms-page-flip.c
index c1c2990..09c2d8f 100644
--- a/src/backends/native/meta-kms-page-flip.c
+++ b/src/backends/native/meta-kms-page-flip.c
@@ -25,6 +25,7 @@
 #include "backends/native/meta-kms-impl.h"
 #include "backends/native/meta-kms-private.h"
 #include "backends/native/meta-kms-update.h"
+#include "backends/native/meta-kms-crtc.h"
 
 typedef struct _MetaKmsPageFlipClosure
 {
@@ -150,6 +151,8 @@ meta_kms_page_flip_data_flipped (MetaKms  *kms,
 
   meta_assert_not_in_kms_impl (kms);
 
+  meta_swap_chain_swap_buffers (meta_kms_crtc_get_swap_chain (page_flip_data->crtc));
+
   for (l = page_flip_data->closures; l; l = l->next)
     {
       MetaKmsPageFlipClosure *closure = l->data;
diff --git a/src/backends/native/meta-kms-update-private.h b/src/backends/native/meta-kms-update-private.h
index 3a648ba..cfcf4b0 100644
--- a/src/backends/native/meta-kms-update-private.h
+++ b/src/backends/native/meta-kms-update-private.h
@@ -137,6 +137,12 @@ uint64_t meta_kms_update_get_sequence_number (MetaKmsUpdate *update);
 META_EXPORT_TEST
 MetaKmsDevice * meta_kms_update_get_device (MetaKmsUpdate *update);
 
+gboolean meta_kms_update_includes_crtc (MetaKmsUpdate *update,
+                                        MetaKmsCrtc   *crtc);
+
+void meta_kms_update_include_crtc (MetaKmsUpdate *update,
+                                   MetaKmsCrtc   *crtc);
+
 void meta_kms_plane_assignment_set_rotation (MetaKmsPlaneAssignment *plane_assignment,
                                              MetaKmsPlaneRotation    rotation);
 
diff --git a/src/backends/native/meta-kms-update.c b/src/backends/native/meta-kms-update.c
index 7a247df..b794bb6 100644
--- a/src/backends/native/meta-kms-update.c
+++ b/src/backends/native/meta-kms-update.c
@@ -25,12 +25,14 @@
 #include "backends/meta-display-config-shared.h"
 #include "backends/native/meta-kms-connector.h"
 #include "backends/native/meta-kms-crtc.h"
+#include "backends/native/meta-kms-device.h"
 #include "backends/native/meta-kms-mode-private.h"
 #include "backends/native/meta-kms-plane.h"
 
 struct _MetaKmsUpdate
 {
   MetaKmsDevice *device;
+  GHashTable *crtcs;
 
   gboolean is_locked;
   uint64_t sequence_number;
@@ -149,6 +151,7 @@ static void
 meta_kms_plane_assignment_free (MetaKmsPlaneAssignment *plane_assignment)
 {
   g_clear_pointer (&plane_assignment->fb_damage, meta_kms_fb_damage_free);
+  g_clear_object (&plane_assignment->buffer);
   g_free (plane_assignment);
 }
 
@@ -228,7 +231,7 @@ meta_kms_update_assign_plane (MetaKmsUpdate          *update,
     .update = update,
     .crtc = crtc,
     .plane = plane,
-    .buffer = buffer,
+    .buffer = g_object_ref (buffer),
     .src_rect = src_rect,
     .dst_rect = dst_rect,
     .flags = flags,
@@ -237,6 +240,8 @@ meta_kms_update_assign_plane (MetaKmsUpdate          *update,
   update->plane_assignments = g_list_prepend (update->plane_assignments,
                                               plane_assignment);
 
+  g_hash_table_add (update->crtcs, crtc);
+
   return plane_assignment;
 }
 
@@ -251,6 +256,8 @@ meta_kms_update_unassign_plane (MetaKmsUpdate *update,
   g_assert (meta_kms_crtc_get_device (crtc) == update->device);
   g_assert (meta_kms_plane_get_device (plane) == update->device);
 
+  drop_plane_assignment (update, plane, NULL);
+
   plane_assignment = g_new0 (MetaKmsPlaneAssignment, 1);
   *plane_assignment = (MetaKmsPlaneAssignment) {
     .update = update,
@@ -262,6 +269,8 @@ meta_kms_update_unassign_plane (MetaKmsUpdate *update,
   update->plane_assignments = g_list_prepend (update->plane_assignments,
                                               plane_assignment);
 
+  g_hash_table_add (update->crtcs, crtc);
+
   return plane_assignment;
 }
 
@@ -284,6 +293,8 @@ meta_kms_update_mode_set (MetaKmsUpdate *update,
   };
 
   update->mode_sets = g_list_prepend (update->mode_sets, mode_set);
+
+  g_hash_table_add (update->crtcs, crtc);
 }
 
 static MetaKmsConnectorUpdate *
@@ -292,6 +303,8 @@ ensure_connector_update (MetaKmsUpdate    *update,
 {
   GList *l;
   MetaKmsConnectorUpdate *connector_update;
+  MetaKmsDevice *device;
+  const MetaKmsConnectorState *state;
 
   for (l = update->connector_updates; l; l = l->next)
     {
@@ -306,6 +319,23 @@ ensure_connector_update (MetaKmsUpdate    *update,
 
   update->connector_updates = g_list_prepend (update->connector_updates,
                                               connector_update);
+  device = meta_kms_connector_get_device (connector);
+  state = meta_kms_connector_get_current_state (connector);
+  if (device && state && state->current_crtc_id)
+    {
+      GList *l;
+
+      for (l = meta_kms_device_get_crtcs (device); l; l = l->next)
+        {
+          MetaKmsCrtc *kms_crtc = l->data;
+
+          if (meta_kms_crtc_get_id (kms_crtc) == state->current_crtc_id)
+            {
+              g_hash_table_add (update->crtcs, kms_crtc);
+              break;
+            }
+        }
+    }
 
   return connector_update;
 }
@@ -416,6 +446,8 @@ meta_kms_update_set_crtc_gamma (MetaKmsUpdate  *update,
   gamma = meta_kms_crtc_gamma_new (crtc, size, red, green, blue);
 
   update->crtc_gammas = g_list_prepend (update->crtc_gammas, gamma);
+
+  g_hash_table_add (update->crtcs, crtc);
 }
 
 void
@@ -657,6 +689,20 @@ meta_kms_update_get_device (MetaKmsUpdate *update)
   return update->device;
 }
 
+gboolean
+meta_kms_update_includes_crtc (MetaKmsUpdate *update,
+                               MetaKmsCrtc   *crtc)
+{
+  return g_hash_table_contains (update->crtcs, crtc);
+}
+
+void
+meta_kms_update_include_crtc (MetaKmsUpdate *update,
+                              MetaKmsCrtc   *crtc)
+{
+  g_hash_table_add (update->crtcs, crtc);
+}
+
 MetaKmsCustomPageFlip *
 meta_kms_update_take_custom_page_flip_func (MetaKmsUpdate *update)
 {
@@ -685,12 +731,15 @@ meta_kms_update_new (MetaKmsDevice *device)
   update->device = device;
   update->sequence_number = sequence_number++;
 
+  update->crtcs = g_hash_table_new (NULL, NULL);
+
   return update;
 }
 
 void
 meta_kms_update_free (MetaKmsUpdate *update)
 {
+  g_hash_table_destroy (update->crtcs);
   g_list_free_full (update->result_listeners,
                     (GDestroyNotify) meta_kms_result_listener_free);
   g_list_free_full (update->plane_assignments,
diff --git a/src/backends/native/meta-kms.c b/src/backends/native/meta-kms.c
index 21be532..b8dba8d 100644
--- a/src/backends/native/meta-kms.c
+++ b/src/backends/native/meta-kms.c
@@ -23,6 +23,7 @@
 #include "backends/native/meta-kms-private.h"
 
 #include "backends/native/meta-backend-native.h"
+#include "backends/native/meta-kms-crtc.h"
 #include "backends/native/meta-kms-device-private.h"
 #include "backends/native/meta-kms-impl.h"
 #include "backends/native/meta-kms-update-private.h"
@@ -177,10 +178,17 @@ struct _MetaKms
 
   GList *pending_callbacks;
   guint callback_source_id;
+
+  gboolean shutting_down;
 };
 
 G_DEFINE_TYPE (MetaKms, meta_kms, G_TYPE_OBJECT)
 
+static MetaKmsFeedback *
+meta_kms_post_update_sync (MetaKms           *kms,
+                           MetaKmsUpdate     *update,
+                           MetaKmsUpdateFlag  flags);
+
 void
 meta_kms_discard_pending_updates (MetaKms *kms)
 {
@@ -247,12 +255,105 @@ meta_kms_take_pending_update (MetaKms       *kms,
   return NULL;
 }
 
+MetaKmsUpdate *
+meta_kms_ensure_pending_update_for_crtc (MetaKms     *kms,
+                                         MetaKmsCrtc *crtc)
+{
+  MetaKmsUpdate *update;
+
+  update = meta_kms_get_pending_update_for_crtc (kms, crtc);
+  if (update == NULL)
+    {
+      update = meta_kms_update_new (meta_kms_crtc_get_device (crtc));
+      meta_kms_update_include_crtc (update, crtc);
+      meta_kms_add_pending_update (kms, update);
+    }
+
+  return update;
+}
+
+static MetaKmsUpdate *
+meta_kms_find_compatible_update_for_crtc (MetaKms     *kms,
+                                          MetaKmsCrtc *crtc,
+                                          gboolean     take)
+{
+  MetaKmsDevice *device;
+  MetaKmsUpdate *update;
+  GList *l;
+
+  for (l = kms->pending_updates; l; l = l->next)
+    {
+      update = l->data;
+      if (meta_kms_update_includes_crtc (update, crtc))
+        goto found;
+    }
+
+  device = meta_kms_crtc_get_device (crtc);
+
+  for (l = kms->pending_updates; l; l = l->next)
+    {
+      update = l->data;
+      if (meta_kms_update_get_device (update) == device &&
+          meta_kms_update_get_mode_sets (update))
+        goto found;
+    }
+
+  return NULL;
+
+found:
+  if (take)
+    kms->pending_updates = g_list_delete_link (kms->pending_updates, l);
+  return update;
+}
+
+MetaKmsUpdate *
+meta_kms_get_pending_update_for_crtc (MetaKms     *kms,
+                                      MetaKmsCrtc *crtc)
+{
+  return meta_kms_find_compatible_update_for_crtc (kms, crtc, FALSE);
+}
+
+static MetaKmsUpdate *
+meta_kms_take_pending_update_for_crtc (MetaKms     *kms,
+                                       MetaKmsCrtc *crtc)
+{
+  return meta_kms_find_compatible_update_for_crtc (kms, crtc, TRUE);
+}
+
 MetaKmsFeedback *
 meta_kms_post_pending_update_sync (MetaKms           *kms,
                                    MetaKmsDevice     *device,
                                    MetaKmsUpdateFlag  flags)
 {
   MetaKmsUpdate *update;
+
+  update = meta_kms_take_pending_update (kms, device);
+  if (!update)
+    return NULL;
+
+  return meta_kms_post_update_sync (kms, update, flags);
+}
+
+MetaKmsFeedback *
+meta_kms_post_pending_update_for_crtc_sync (MetaKms           *kms,
+                                            MetaKmsCrtc       *crtc,
+                                            MetaKmsUpdateFlag  flags)
+{
+  MetaKmsUpdate *update;
+
+  update = meta_kms_take_pending_update_for_crtc (kms, crtc);
+  if (!update)
+    return NULL;
+
+  return meta_kms_post_update_sync (kms, update, flags);
+}
+
+static MetaKmsFeedback *
+meta_kms_post_update_sync (MetaKms           *kms,
+                           MetaKmsUpdate     *update,
+                           MetaKmsUpdateFlag  flags)
+{
+  MetaKmsDevice *device = meta_kms_update_get_device (update);
   MetaKmsFeedback *feedback;
   GList *result_listeners;
   GList *l;
@@ -260,10 +361,6 @@ meta_kms_post_pending_update_sync (MetaKms           *kms,
   COGL_TRACE_BEGIN_SCOPED (MetaKmsPostUpdateSync,
                            "KMS (post update)");
 
-  update = meta_kms_take_pending_update (kms, device);
-  if (!update)
-    return NULL;
-
   meta_kms_update_lock (update);
 
   feedback = meta_kms_device_process_update_sync (device, update, flags);
@@ -752,10 +849,18 @@ prepare_shutdown_in_impl (MetaKmsImpl  *impl,
 void
 meta_kms_prepare_shutdown (MetaKms *kms)
 {
+  kms->shutting_down = TRUE;
+
   meta_kms_run_impl_task_sync (kms, prepare_shutdown_in_impl, NULL, NULL);
   flush_callbacks (kms);
 }
 
+gboolean
+meta_kms_is_shutting_down (MetaKms *kms)
+{
+  return kms->shutting_down;
+}
+
 static void
 meta_kms_finalize (GObject *object)
 {
diff --git a/src/backends/native/meta-kms.h b/src/backends/native/meta-kms.h
index bd9fe5c..e8fe2e4 100644
--- a/src/backends/native/meta-kms.h
+++ b/src/backends/native/meta-kms.h
@@ -39,9 +39,15 @@ void meta_kms_discard_pending_updates (MetaKms *kms);
 MetaKmsUpdate * meta_kms_ensure_pending_update (MetaKms       *kms,
                                                 MetaKmsDevice *device);
 
+MetaKmsUpdate * meta_kms_ensure_pending_update_for_crtc (MetaKms     *kms,
+                                                         MetaKmsCrtc *crtc);
+
 MetaKmsUpdate * meta_kms_get_pending_update (MetaKms       *kms,
                                              MetaKmsDevice *device);
 
+MetaKmsUpdate * meta_kms_get_pending_update_for_crtc (MetaKms     *kms,
+                                                      MetaKmsCrtc *crtc);
+
 MetaKmsFeedback * meta_kms_post_pending_update_sync (MetaKms           *kms,
                                                      MetaKmsDevice     *device,
                                                      MetaKmsUpdateFlag  flags);
@@ -49,6 +55,10 @@ MetaKmsFeedback * meta_kms_post_pending_update_sync (MetaKms           *kms,
 MetaKmsFeedback * meta_kms_post_test_update_sync (MetaKms       *kms,
                                                   MetaKmsUpdate *update);
 
+MetaKmsFeedback * meta_kms_post_pending_update_for_crtc_sync (MetaKms           *kms,
+                                                              MetaKmsCrtc       *device,
+                                                              MetaKmsUpdateFlag  flags);
+
 void meta_kms_discard_pending_page_flips (MetaKms *kms);
 
 void meta_kms_notify_modes_set (MetaKms *kms);
@@ -68,6 +78,8 @@ MetaKmsDevice * meta_kms_create_device (MetaKms            *kms,
 
 void meta_kms_prepare_shutdown (MetaKms *kms);
 
+gboolean meta_kms_is_shutting_down (MetaKms *kms);
+
 MetaKms * meta_kms_new (MetaBackend   *backend,
                         MetaKmsFlags   flags,
                         GError       **error);
diff --git a/src/backends/native/meta-onscreen-native.c b/src/backends/native/meta-onscreen-native.c
index b3f53b4..d82ea35 100644
--- a/src/backends/native/meta-onscreen-native.c
+++ b/src/backends/native/meta-onscreen-native.c
@@ -71,7 +71,7 @@ typedef struct _MetaOnscreenNativeSecondaryGpuState
 
   struct {
     MetaDrmBufferDumb *current_dumb_fb;
-    MetaDrmBufferDumb *dumb_fbs[2];
+    MetaDrmBufferDumb *dumb_fbs[3];
   } cpu;
 
   gboolean noted_primary_gpu_copy_ok;
@@ -92,8 +92,8 @@ struct _MetaOnscreenNative
 
   struct {
     struct gbm_surface *surface;
-    MetaDrmBuffer *current_fb;
     MetaDrmBuffer *next_fb;
+    MetaDrmBuffer *stalled_fb;
   } gbm;
 
 #ifdef HAVE_EGL_DEVICE
@@ -108,6 +108,13 @@ struct _MetaOnscreenNative
 
   gboolean is_gamma_lut_invalid;
   gboolean is_privacy_screen_invalid;
+
+  unsigned int swaps_pending;
+
+  struct {
+    int *rectangles;  /* 4 x n_rectangles */
+    int n_rectangles;
+  } next_post;
 };
 
 G_DEFINE_TYPE (MetaOnscreenNative, meta_onscreen_native,
@@ -115,33 +122,14 @@ G_DEFINE_TYPE (MetaOnscreenNative, meta_onscreen_native,
 
 static GQuark blit_source_quark = 0;
 
+static void
+try_post_latest_swap (CoglOnscreen *onscreen);
+
 static gboolean
 init_secondary_gpu_state (MetaRendererNative  *renderer_native,
                           CoglOnscreen        *onscreen,
                           GError             **error);
 
-static void
-free_current_bo (CoglOnscreen *onscreen)
-{
-  MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
-
-  g_clear_object (&onscreen_native->gbm.current_fb);
-}
-
-static void
-meta_onscreen_native_swap_drm_fb (CoglOnscreen *onscreen)
-{
-  MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
-
-  if (!onscreen_native->gbm.next_fb)
-    return;
-
-  free_current_bo (onscreen);
-
-  g_set_object (&onscreen_native->gbm.current_fb, onscreen_native->gbm.next_fb);
-  g_clear_object (&onscreen_native->gbm.next_fb);
-}
-
 static void
 maybe_update_frame_info (MetaCrtc         *crtc,
                          CoglFrameInfo    *frame_info,
@@ -177,7 +165,7 @@ meta_onscreen_native_notify_frame_complete (CoglOnscreen *onscreen)
 
   info = cogl_onscreen_pop_head_frame_info (onscreen);
 
-  g_assert (!cogl_onscreen_peek_head_frame_info (onscreen));
+  g_assert (info);
 
   _cogl_onscreen_notify_frame_sync (onscreen, info);
   _cogl_onscreen_notify_complete (onscreen, info);
@@ -210,7 +198,7 @@ notify_view_crtc_presented (MetaRendererView *view,
   maybe_update_frame_info (crtc, frame_info, time_us, flags, sequence);
 
   meta_onscreen_native_notify_frame_complete (onscreen);
-  meta_onscreen_native_swap_drm_fb (onscreen);
+  try_post_latest_swap (onscreen);
 }
 
 static int64_t
@@ -272,6 +260,7 @@ page_flip_feedback_ready (MetaKmsCrtc *kms_crtc,
   frame_info->flags |= COGL_FRAME_INFO_FLAG_SYMBOLIC;
 
   meta_onscreen_native_notify_frame_complete (onscreen);
+  try_post_latest_swap (onscreen);
 }
 
 static void
@@ -321,7 +310,7 @@ page_flip_feedback_discarded (MetaKmsCrtc  *kms_crtc,
   frame_info->flags |= COGL_FRAME_INFO_FLAG_SYMBOLIC;
 
   meta_onscreen_native_notify_frame_complete (onscreen);
-  meta_onscreen_native_swap_drm_fb (onscreen);
+  try_post_latest_swap (onscreen);
 }
 
 static const MetaKmsPageFlipListenerVtable page_flip_listener_vtable = {
@@ -382,18 +371,40 @@ custom_egl_stream_page_flip (gpointer custom_page_flip_data,
 }
 #endif /* HAVE_EGL_DEVICE */
 
-void
-meta_onscreen_native_dummy_power_save_page_flip (CoglOnscreen *onscreen)
+static void
+drop_stalled_swap (CoglOnscreen *onscreen)
 {
+  MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
   CoglFrameInfo *frame_info;
 
-  meta_onscreen_native_swap_drm_fb (onscreen);
+  /* Remember we can't compare stalled_fb because it's not used by
+   * META_RENDERER_NATIVE_MODE_EGL_DEVICE. So we judge stalled to be whenever
+   * swaps_pending > 1.
+   */
+  if (onscreen_native->swaps_pending <= 1)
+    return;
+
+  onscreen_native->swaps_pending--;
+
+  g_clear_object (&onscreen_native->gbm.stalled_fb);
 
   frame_info = cogl_onscreen_peek_tail_frame_info (onscreen);
   frame_info->flags |= COGL_FRAME_INFO_FLAG_SYMBOLIC;
   meta_onscreen_native_notify_frame_complete (onscreen);
 }
 
+void
+meta_onscreen_native_dummy_power_save_page_flip (CoglOnscreen *onscreen)
+{
+  drop_stalled_swap (onscreen);
+
+  /* If the monitor just woke up and the shell is fully idle (has nothing
+   * more to swap) then we just woke to an indefinitely black screen. Let's
+   * fix that using the last swap (which is never classified as "stalled").
+   */
+  try_post_latest_swap (onscreen);
+}
+
 static void
 meta_onscreen_native_flip_crtc (CoglOnscreen                *onscreen,
                                 MetaRendererView            *view,
@@ -412,7 +423,7 @@ meta_onscreen_native_flip_crtc (CoglOnscreen                *onscreen,
   MetaKmsDevice *kms_device;
   MetaKms *kms;
   MetaKmsUpdate *kms_update;
-  MetaDrmBuffer *buffer;
+  g_autoptr (MetaDrmBuffer) buffer = NULL;
   MetaKmsPlaneAssignment *plane_assignment;
 
   COGL_TRACE_BEGIN_SCOPED (MetaOnscreenNativeFlipCrtcs,
@@ -421,7 +432,7 @@ meta_onscreen_native_flip_crtc (CoglOnscreen                *onscreen,
   gpu_kms = META_GPU_KMS (meta_crtc_get_gpu (crtc));
   kms_device = meta_gpu_kms_get_kms_device (gpu_kms);
   kms = meta_kms_device_get_kms (kms_device);
-  kms_update = meta_kms_ensure_pending_update (kms, kms_device);
+  kms_update = meta_kms_ensure_pending_update_for_crtc (kms, kms_crtc);
 
   g_assert (meta_gpu_kms_is_crtc_active (gpu_kms, crtc));
 
@@ -430,7 +441,7 @@ meta_onscreen_native_flip_crtc (CoglOnscreen                *onscreen,
   switch (renderer_gpu_data->mode)
     {
     case META_RENDERER_NATIVE_MODE_GBM:
-      buffer = onscreen_native->gbm.next_fb;
+      buffer = g_steal_pointer (&onscreen_native->gbm.next_fb);
 
       plane_assignment = meta_crtc_kms_assign_primary_plane (crtc_kms,
                                                              buffer,
@@ -441,6 +452,11 @@ meta_onscreen_native_flip_crtc (CoglOnscreen                *onscreen,
           meta_kms_plane_assignment_set_fb_damage (plane_assignment,
                                                    rectangles, n_rectangles);
         }
+
+      g_object_set_data_full (G_OBJECT (buffer),
+                              "gbm_surface owner",
+                              g_object_ref (onscreen),
+                              (GDestroyNotify) g_object_unref);
       break;
     case META_RENDERER_NATIVE_MODE_SURFACELESS:
       g_assert_not_reached ();
@@ -476,7 +492,7 @@ meta_onscreen_native_set_crtc_mode (CoglOnscreen              *onscreen,
   COGL_TRACE_BEGIN_SCOPED (MetaOnscreenNativeSetCrtcModes,
                            "Onscreen (set CRTC modes)");
 
-  kms_update = meta_kms_ensure_pending_update (kms, kms_device);
+  kms_update = meta_kms_ensure_pending_update_for_crtc (kms, kms_crtc);
 
   switch (renderer_gpu_data->mode)
     {
@@ -687,12 +703,17 @@ static MetaDrmBufferDumb *
 secondary_gpu_get_next_dumb_buffer (MetaOnscreenNativeSecondaryGpuState *secondary_gpu_state)
 {
   MetaDrmBufferDumb *current_dumb_fb;
+  const int n_dumb_fbs = G_N_ELEMENTS (secondary_gpu_state->cpu.dumb_fbs);
+  int i;
 
   current_dumb_fb = secondary_gpu_state->cpu.current_dumb_fb;
-  if (current_dumb_fb == secondary_gpu_state->cpu.dumb_fbs[0])
-    return secondary_gpu_state->cpu.dumb_fbs[1];
-  else
-    return secondary_gpu_state->cpu.dumb_fbs[0];
+  for (i = 0; i < n_dumb_fbs; i++)
+    {
+      if (current_dumb_fb == secondary_gpu_state->cpu.dumb_fbs[i])
+        return secondary_gpu_state->cpu.dumb_fbs[(i + 1) % n_dumb_fbs];
+    }
+
+  return secondary_gpu_state->cpu.dumb_fbs[0];
 }
 
 static MetaDrmBuffer *
@@ -1017,33 +1038,35 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
   CoglRendererEGL *cogl_renderer_egl = cogl_renderer->winsys;
   MetaRendererNativeGpuData *renderer_gpu_data = cogl_renderer_egl->platform;
   MetaRendererNative *renderer_native = renderer_gpu_data->renderer_native;
-  MetaRenderer *renderer = META_RENDERER (renderer_native);
-  MetaBackend *backend = meta_renderer_get_backend (renderer);
-  MetaBackendNative *backend_native = META_BACKEND_NATIVE (backend);
-  MetaMonitorManager *monitor_manager =
-    meta_backend_get_monitor_manager (backend);
-  MetaKms *kms = meta_backend_native_get_kms (backend_native);
   MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
   MetaGpuKms *render_gpu = onscreen_native->render_gpu;
   MetaDeviceFile *render_device_file;
   ClutterFrame *frame = user_data;
   CoglOnscreenClass *parent_class;
   gboolean egl_context_changed = FALSE;
-  MetaPowerSave power_save_mode;
   g_autoptr (GError) error = NULL;
   MetaDrmBufferFlags buffer_flags;
   MetaDrmBufferGbm *buffer_gbm;
   g_autoptr (MetaDrmBuffer) primary_gpu_fb = NULL;
   g_autoptr (MetaDrmBuffer) secondary_gpu_fb = NULL;
-  MetaKmsCrtc *kms_crtc;
-  MetaKmsDevice *kms_device;
-  MetaKmsUpdateFlag flags;
-  g_autoptr (MetaKmsFeedback) kms_feedback = NULL;
-  const GError *feedback_error;
+  size_t rectangles_size;
 
   COGL_TRACE_BEGIN_SCOPED (MetaRendererNativeSwapBuffers,
                            "Onscreen (swap-buffers)");
 
+  if (meta_is_topic_enabled (META_DEBUG_KMS))
+    {
+      unsigned int frames_pending =
+        cogl_onscreen_count_pending_frames (onscreen);
+
+      meta_topic (META_DEBUG_KMS,
+                  "Swap buffers: %u frames pending (%s-buffering)",
+                  frames_pending,
+                  frames_pending == 1 ? "double" :
+                  frames_pending == 2 ? "triple" :
+                  "?");
+    }
+
   secondary_gpu_fb =
     update_secondary_gpu_state_pre_swap_buffers (onscreen,
                                                  rectangles,
@@ -1099,7 +1122,15 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
   switch (renderer_gpu_data->mode)
     {
     case META_RENDERER_NATIVE_MODE_GBM:
-      g_warn_if_fail (onscreen_native->gbm.next_fb == NULL);
+      if (onscreen_native->gbm.next_fb != NULL)
+        {
+          g_warn_if_fail (onscreen_native->gbm.stalled_fb == NULL);
+          drop_stalled_swap (onscreen);
+          g_assert (onscreen_native->gbm.stalled_fb == NULL);
+          onscreen_native->gbm.stalled_fb =
+            g_steal_pointer (&onscreen_native->gbm.next_fb);
+        }
+
       if (onscreen_native->secondary_gpu_state)
         g_set_object (&onscreen_native->gbm.next_fb, secondary_gpu_fb);
       else
@@ -1113,6 +1144,9 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
 #endif
     }
 
+  clutter_frame_set_result (frame,
+                            CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
+
   /*
    * If we changed EGL context, cogl will have the wrong idea about what is
    * current, making it fail to set it when it needs to. Avoid that by making
@@ -1122,23 +1156,77 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
   if (egl_context_changed)
     _cogl_winsys_egl_ensure_current (cogl_display);
 
+  rectangles_size = n_rectangles * 4 * sizeof (int);
+  onscreen_native->next_post.rectangles =
+    g_realloc (onscreen_native->next_post.rectangles, rectangles_size);
+  memcpy (onscreen_native->next_post.rectangles, rectangles, rectangles_size);
+  onscreen_native->next_post.n_rectangles = n_rectangles;
+
+  onscreen_native->swaps_pending++;
+  try_post_latest_swap (onscreen);
+}
+
+static void
+try_post_latest_swap (CoglOnscreen *onscreen)
+{
+  CoglFramebuffer *framebuffer = COGL_FRAMEBUFFER (onscreen);
+  CoglContext *cogl_context = cogl_framebuffer_get_context (framebuffer);
+  CoglRenderer *cogl_renderer = cogl_context->display->renderer;
+  CoglRendererEGL *cogl_renderer_egl = cogl_renderer->winsys;
+  MetaRendererNativeGpuData *renderer_gpu_data = cogl_renderer_egl->platform;
+  MetaRendererNative *renderer_native = renderer_gpu_data->renderer_native;
+  MetaRenderer *renderer = META_RENDERER (renderer_native);
+  MetaBackend *backend = meta_renderer_get_backend (renderer);
+  MetaBackendNative *backend_native = META_BACKEND_NATIVE (backend);
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaKms *kms = meta_backend_native_get_kms (backend_native);
+  MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
+  MetaPowerSave power_save_mode;
+  MetaCrtcKms *crtc_kms = META_CRTC_KMS (onscreen_native->crtc);
+  MetaKmsCrtc *kms_crtc = meta_crtc_kms_get_kms_crtc (crtc_kms);
+  MetaKmsDevice *kms_device = meta_kms_crtc_get_device (kms_crtc);
+  MetaKmsUpdateFlag flags;
+  g_autoptr (MetaKmsFeedback) kms_feedback = NULL;
+  const GError *feedback_error;
+  unsigned int frames_pending = cogl_onscreen_count_pending_frames (onscreen);
+
+  if (meta_kms_is_shutting_down (kms))
+    {
+      meta_onscreen_native_discard_pending_swaps (onscreen);
+      return;
+    }
+
+  if (onscreen_native->swaps_pending == 0)
+    return;
+
+  g_assert (frames_pending >= onscreen_native->swaps_pending);
+
   power_save_mode = meta_monitor_manager_get_power_save_mode (monitor_manager);
   if (power_save_mode == META_POWER_SAVE_ON)
     {
+      unsigned int posts_pending;
+
+      posts_pending = frames_pending - onscreen_native->swaps_pending;
+      if (posts_pending > 0)
+        return;  /* wait for the next frame notification and then try again */
+
+      drop_stalled_swap (onscreen);
+      g_return_if_fail (onscreen_native->swaps_pending > 0);
+      onscreen_native->swaps_pending--;
+
       ensure_crtc_modes (onscreen);
       meta_onscreen_native_flip_crtc (onscreen,
                                       onscreen_native->view,
                                       onscreen_native->crtc,
                                       META_KMS_PAGE_FLIP_LISTENER_FLAG_NONE,
-                                      rectangles,
-                                      n_rectangles);
+                                      onscreen_native->next_post.rectangles,
+                                      onscreen_native->next_post.n_rectangles);
     }
   else
     {
       meta_renderer_native_queue_power_save_page_flip (renderer_native,
                                                        onscreen);
-      clutter_frame_set_result (frame,
-                                CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
       return;
     }
 
@@ -1156,9 +1244,6 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
                       "Postponing primary plane composite update for CRTC %u (%s)",
                       meta_kms_crtc_get_id (kms_crtc),
                       meta_kms_device_get_path (kms_device));
-
-          clutter_frame_set_result (frame,
-                                    CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
           return;
         }
       else if (meta_renderer_native_has_pending_mode_set (renderer_native))
@@ -1168,8 +1253,6 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
 
           meta_renderer_native_notify_mode_sets_reset (renderer_native);
           meta_renderer_native_post_mode_set_updates (renderer_native);
-          clutter_frame_set_result (frame,
-                                    CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
           return;
         }
       break;
@@ -1182,8 +1265,6 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
         {
           meta_renderer_native_notify_mode_sets_reset (renderer_native);
           meta_renderer_native_post_mode_set_updates (renderer_native);
-          clutter_frame_set_result (frame,
-                                    CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
           return;
         }
       break;
@@ -1196,18 +1277,16 @@ meta_onscreen_native_swap_buffers_with_damage (CoglOnscreen  *onscreen,
               meta_kms_device_get_path (kms_device));
 
   flags = META_KMS_UPDATE_FLAG_NONE;
-  kms_feedback = meta_kms_post_pending_update_sync (kms, kms_device, flags);
+  kms_feedback = meta_kms_post_pending_update_for_crtc_sync (kms,
+                                                             kms_crtc,
+                                                             flags);
+  g_return_if_fail (kms_feedback != NULL);
 
   switch (meta_kms_feedback_get_result (kms_feedback))
     {
     case META_KMS_FEEDBACK_PASSED:
-      clutter_frame_set_result (frame,
-                                CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
       break;
     case META_KMS_FEEDBACK_FAILED:
-      clutter_frame_set_result (frame,
-                                CLUTTER_FRAME_RESULT_PENDING_PRESENTED);
-
       feedback_error = meta_kms_feedback_get_error (kms_feedback);
       if (!g_error_matches (feedback_error,
                             G_IO_ERROR,
@@ -1294,6 +1373,18 @@ meta_onscreen_native_direct_scanout (CoglOnscreen   *onscreen,
       return FALSE;
     }
 
+  /* Our direct scanout frame counts as 1, so more than that means we would
+   * be jumping the queue (and post would fail).
+   */
+  if (cogl_onscreen_count_pending_frames (onscreen) > 1)
+    {
+      g_set_error_literal (error,
+                           COGL_SCANOUT_ERROR,
+                           COGL_SCANOUT_ERROR_INHIBITED,
+                           "Direct scanout is inhibited during triple buffering");
+      return FALSE;
+    }
+
   renderer_gpu_data = meta_renderer_native_get_gpu_data (renderer_native,
                                                          render_gpu);
 
@@ -1346,7 +1437,9 @@ meta_onscreen_native_direct_scanout (CoglOnscreen   *onscreen,
               meta_kms_device_get_path (kms_device));
 
   flags = META_KMS_UPDATE_FLAG_PRESERVE_ON_ERROR;
-  kms_feedback = meta_kms_post_pending_update_sync (kms, kms_device, flags);
+  kms_feedback = meta_kms_post_pending_update_for_crtc_sync (kms,
+                                                             kms_crtc,
+                                                             flags);
   switch (meta_kms_feedback_get_result (kms_feedback))
     {
     case META_KMS_FEEDBACK_PASSED:
@@ -1360,7 +1453,6 @@ meta_onscreen_native_direct_scanout (CoglOnscreen   *onscreen,
                            G_IO_ERROR, G_IO_ERROR_PERMISSION_DENIED))
         break;
 
-      g_clear_object (&onscreen_native->gbm.next_fb);
       g_propagate_error (error, g_error_copy (feedback_error));
       return FALSE;
     }
@@ -1402,7 +1494,7 @@ meta_onscreen_native_prepare_frame (CoglOnscreen *onscreen,
         {
           MetaKmsUpdate *kms_update;
 
-          kms_update = meta_kms_ensure_pending_update (kms, kms_device);
+          kms_update = meta_kms_ensure_pending_update_for_crtc (kms, kms_crtc);
           meta_kms_update_set_crtc_gamma (kms_update,
                                           kms_crtc,
                                           gamma->size,
@@ -1419,7 +1511,7 @@ meta_onscreen_native_prepare_frame (CoglOnscreen *onscreen,
       MetaKmsUpdate *kms_update;
       gboolean enabled;
 
-      kms_update = meta_kms_ensure_pending_update (kms, kms_device);
+      kms_update = meta_kms_ensure_pending_update_for_crtc (kms, kms_crtc);
 
       enabled = meta_output_is_privacy_screen_enabled (onscreen_native->output);
       meta_kms_update_set_privacy_screen (kms_update, kms_connector, enabled);
@@ -1440,7 +1532,10 @@ meta_onscreen_native_finish_frame (CoglOnscreen *onscreen,
   g_autoptr (MetaKmsFeedback) kms_feedback = NULL;
   const GError *error;
 
-  kms_update = meta_kms_get_pending_update (kms, kms_device);
+  if (cogl_onscreen_count_pending_frames (onscreen) > 0)
+    return;
+
+  kms_update = meta_kms_get_pending_update_for_crtc (kms, kms_crtc);
   if (!kms_update)
     {
       clutter_frame_set_result (frame, CLUTTER_FRAME_RESULT_IDLE);
@@ -1455,9 +1550,9 @@ meta_onscreen_native_finish_frame (CoglOnscreen *onscreen,
                                           g_object_unref);
 
   flags = META_KMS_UPDATE_FLAG_NONE;
-  kms_feedback = meta_kms_post_pending_update_sync (kms,
-                                                    kms_device,
-                                                    flags);
+  kms_feedback = meta_kms_post_pending_update_for_crtc_sync (kms,
+                                                             kms_crtc,
+                                                             flags);
   switch (meta_kms_feedback_get_result (kms_feedback))
     {
     case META_KMS_FEEDBACK_PASSED:
@@ -1479,6 +1574,17 @@ meta_onscreen_native_finish_frame (CoglOnscreen *onscreen,
     }
 }
 
+void
+meta_onscreen_native_discard_pending_swaps (CoglOnscreen *onscreen)
+{
+  MetaOnscreenNative *onscreen_native = META_ONSCREEN_NATIVE (onscreen);
+
+  onscreen_native->swaps_pending = 0;
+
+  g_clear_object (&onscreen_native->gbm.stalled_fb);
+  g_clear_object (&onscreen_native->gbm.next_fb);
+}
+
 static gboolean
 should_surface_be_sharable (CoglOnscreen *onscreen)
 {
@@ -2202,7 +2308,7 @@ meta_onscreen_native_new (MetaRendererNative *renderer_native,
   onscreen_native->renderer_native = renderer_native;
   onscreen_native->render_gpu = render_gpu;
   onscreen_native->output = output;
-  onscreen_native->crtc = crtc;
+  onscreen_native->crtc = g_object_ref (crtc);
 
   if (meta_crtc_get_gamma_lut_size (crtc) > 0)
     {
@@ -2239,7 +2345,6 @@ meta_onscreen_native_dispose (GObject *object)
     {
     case META_RENDERER_NATIVE_MODE_GBM:
       g_clear_object (&onscreen_native->gbm.next_fb);
-      free_current_bo (onscreen);
       break;
     case META_RENDERER_NATIVE_MODE_SURFACELESS:
       g_assert_not_reached ();
@@ -2267,9 +2372,12 @@ meta_onscreen_native_dispose (GObject *object)
 
   G_OBJECT_CLASS (meta_onscreen_native_parent_class)->dispose (object);
 
+  g_clear_object (&onscreen_native->crtc);
   g_clear_pointer (&onscreen_native->gbm.surface, gbm_surface_destroy);
   g_clear_pointer (&onscreen_native->secondary_gpu_state,
                    secondary_gpu_state_free);
+  g_clear_pointer (&onscreen_native->next_post.rectangles, g_free);
+  onscreen_native->next_post.n_rectangles = 0;
 }
 
 static void
diff --git a/src/backends/native/meta-onscreen-native.h b/src/backends/native/meta-onscreen-native.h
index 5c6af82..6ad1905 100644
--- a/src/backends/native/meta-onscreen-native.h
+++ b/src/backends/native/meta-onscreen-native.h
@@ -45,6 +45,8 @@ void meta_onscreen_native_finish_frame (CoglOnscreen *onscreen,
 
 void meta_onscreen_native_dummy_power_save_page_flip (CoglOnscreen *onscreen);
 
+void meta_onscreen_native_discard_pending_swaps (CoglOnscreen *onscreen);
+
 gboolean meta_onscreen_native_is_buffer_scanout_compatible (CoglOnscreen  *onscreen,
                                                             MetaDrmBuffer *fb);
 
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index f8de8b3..e5ac471 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -689,12 +689,18 @@ static gboolean
 dummy_power_save_page_flip_cb (gpointer user_data)
 {
   MetaRendererNative *renderer_native = user_data;
+  GList *old_list =
+    g_steal_pointer (&renderer_native->power_save_page_flip_onscreens);
 
-  g_list_foreach (renderer_native->power_save_page_flip_onscreens,
+  g_list_foreach (old_list,
                   (GFunc) meta_onscreen_native_dummy_power_save_page_flip,
                   NULL);
-  g_clear_list (&renderer_native->power_save_page_flip_onscreens,
+  g_clear_list (&old_list,
                 g_object_unref);
+
+  if (renderer_native->power_save_page_flip_onscreens != NULL)
+    return G_SOURCE_CONTINUE;
+
   renderer_native->power_save_page_flip_source_id = 0;
 
   return G_SOURCE_REMOVE;
@@ -706,6 +712,9 @@ meta_renderer_native_queue_power_save_page_flip (MetaRendererNative *renderer_na
 {
   const unsigned int timeout_ms = 100;
 
+  if (g_list_find (renderer_native->power_save_page_flip_onscreens, onscreen))
+    return;
+
   if (!renderer_native->power_save_page_flip_source_id)
     {
       renderer_native->power_save_page_flip_source_id =
@@ -1414,6 +1423,26 @@ meta_renderer_native_create_view (MetaRenderer       *renderer,
   return view;
 }
 
+static void
+discard_pending_swaps (MetaRenderer *renderer)
+{
+  GList *views = meta_renderer_get_views (renderer);;
+  GList *l;
+
+  for (l = views; l; l = l->next)
+    {
+      ClutterStageView *stage_view = l->data;
+      CoglFramebuffer *fb = clutter_stage_view_get_onscreen (stage_view);
+      CoglOnscreen *onscreen;
+
+      if (!COGL_IS_ONSCREEN (fb))
+        continue;
+
+      onscreen = COGL_ONSCREEN (fb);
+      meta_onscreen_native_discard_pending_swaps (onscreen);
+    }
+}
+
 static void
 keep_current_onscreens_alive (MetaRenderer *renderer)
 {
@@ -1442,6 +1471,7 @@ meta_renderer_native_rebuild_views (MetaRenderer *renderer)
   MetaRendererClass *parent_renderer_class =
     META_RENDERER_CLASS (meta_renderer_native_parent_class);
 
+  discard_pending_swaps (renderer);
   meta_kms_discard_pending_page_flips (kms);
   meta_kms_discard_pending_updates (kms);
 
diff --git a/src/backends/native/meta-swap-chain.c b/src/backends/native/meta-swap-chain.c
new file mode 100644
index 0000000..c3bed56
--- /dev/null
+++ b/src/backends/native/meta-swap-chain.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2022 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Author: Daniel van Vugt <daniel.van.vugt@canonical.com>
+ */
+
+#include "backends/native/meta-swap-chain.h"
+
+typedef struct
+{
+  GObject *front, *back;
+  gboolean back_is_set;
+} PlaneState;
+
+typedef struct _MetaSwapChainPrivate MetaSwapChainPrivate;
+struct _MetaSwapChainPrivate
+{
+  GHashTable *plane_states;
+};
+
+G_DEFINE_TYPE_WITH_PRIVATE (MetaSwapChain, meta_swap_chain, G_TYPE_OBJECT)
+
+MetaSwapChain *
+meta_swap_chain_new (void)
+{
+  return g_object_new (META_TYPE_SWAP_CHAIN, NULL);
+}
+
+void
+meta_swap_chain_push_buffer (MetaSwapChain *swap_chain,
+                             unsigned int   plane_id,
+                             GObject       *buffer)
+{
+  MetaSwapChainPrivate *priv =
+    meta_swap_chain_get_instance_private (swap_chain);
+  gpointer key = GUINT_TO_POINTER (plane_id);
+  PlaneState *plane_state;
+
+  plane_state = g_hash_table_lookup (priv->plane_states, key);
+  if (plane_state == NULL)
+    {
+      plane_state = g_new0 (PlaneState, 1);
+      g_hash_table_insert (priv->plane_states, key, plane_state);
+    }
+
+  plane_state->back_is_set = TRUE;  /* note buffer may be NULL */
+  g_set_object (&plane_state->back, buffer);
+}
+
+static void
+swap_plane_buffers (gpointer key,
+                    gpointer value,
+                    gpointer user_data)
+{
+  PlaneState *plane_state = value;
+
+  if (plane_state->back_is_set)
+    {
+      g_set_object (&plane_state->front, plane_state->back);
+      g_clear_object (&plane_state->back);
+      plane_state->back_is_set = FALSE;
+    }
+}
+
+void
+meta_swap_chain_swap_buffers (MetaSwapChain *swap_chain)
+{
+  MetaSwapChainPrivate *priv =
+    meta_swap_chain_get_instance_private (swap_chain);
+
+  g_hash_table_foreach (priv->plane_states, swap_plane_buffers, NULL);
+}
+
+void
+meta_swap_chain_release_buffers (MetaSwapChain *swap_chain)
+{
+  MetaSwapChainPrivate *priv =
+    meta_swap_chain_get_instance_private (swap_chain);
+
+  g_hash_table_remove_all (priv->plane_states);
+}
+
+static void
+meta_swap_chain_dispose (GObject *object)
+{
+  MetaSwapChain *swap_chain = META_SWAP_CHAIN (object);
+
+  meta_swap_chain_release_buffers (swap_chain);
+
+  G_OBJECT_CLASS (meta_swap_chain_parent_class)->dispose (object);
+}
+
+static void
+meta_swap_chain_finalize (GObject *object)
+{
+  MetaSwapChain *swap_chain = META_SWAP_CHAIN (object);
+  MetaSwapChainPrivate *priv =
+    meta_swap_chain_get_instance_private (swap_chain);
+
+  g_hash_table_unref (priv->plane_states);
+
+  G_OBJECT_CLASS (meta_swap_chain_parent_class)->finalize (object);
+}
+
+static void
+destroy_plane_state (gpointer data)
+{
+  PlaneState *plane_state = data;
+
+  g_clear_object (&plane_state->front);
+  g_clear_object (&plane_state->back);
+  g_free (plane_state);
+}
+
+static void
+meta_swap_chain_init (MetaSwapChain *swap_chain)
+{
+  MetaSwapChainPrivate *priv =
+    meta_swap_chain_get_instance_private (swap_chain);
+
+  priv->plane_states = g_hash_table_new_full (NULL,
+                                              NULL,
+                                              NULL,
+                                              destroy_plane_state);
+}
+
+static void
+meta_swap_chain_class_init (MetaSwapChainClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = meta_swap_chain_dispose;
+  object_class->finalize = meta_swap_chain_finalize;
+}
diff --git a/src/backends/native/meta-swap-chain.h b/src/backends/native/meta-swap-chain.h
new file mode 100644
index 0000000..bad772b
--- /dev/null
+++ b/src/backends/native/meta-swap-chain.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2022 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Author: Daniel van Vugt <daniel.van.vugt@canonical.com>
+ */
+
+#ifndef META_SWAP_CHAIN_H
+#define META_SWAP_CHAIN_H
+
+#include <glib-object.h>
+
+#define META_TYPE_SWAP_CHAIN (meta_swap_chain_get_type ())
+G_DECLARE_DERIVABLE_TYPE (MetaSwapChain,
+                          meta_swap_chain,
+                          META, SWAP_CHAIN,
+                          GObject)
+
+struct _MetaSwapChainClass
+{
+  GObjectClass parent_class;
+};
+
+MetaSwapChain * meta_swap_chain_new (void);
+
+void meta_swap_chain_push_buffer (MetaSwapChain *swap_chain,
+                                  unsigned int   plane_id,
+                                  GObject       *buffer);
+
+void meta_swap_chain_swap_buffers (MetaSwapChain *swap_chain);
+
+void meta_swap_chain_release_buffers (MetaSwapChain *swap_chain);
+
+#endif /* META_SWAP_CHAIN_H */
diff --git a/src/meson.build b/src/meson.build
index 2eee063..19182e6 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -816,6 +816,8 @@ if have_native_backend
     'backends/native/meta-seat-native.h',
     'backends/native/meta-stage-native.c',
     'backends/native/meta-stage-native.h',
+    'backends/native/meta-swap-chain.c',
+    'backends/native/meta-swap-chain.h',
     'backends/native/meta-udev.c',
     'backends/native/meta-udev.h',
     'backends/native/meta-virtual-input-device-native.c',
diff --git a/src/tests/native-kms-render.c b/src/tests/native-kms-render.c
index 2153623..7611aa4 100644
--- a/src/tests/native-kms-render.c
+++ b/src/tests/native-kms-render.c
@@ -36,6 +36,8 @@
 #include "tests/meta-wayland-test-driver.h"
 #include "tests/meta-wayland-test-utils.h"
 
+#define N_FRAMES_PER_TEST 10
+
 typedef struct
 {
   int number_of_frames_left;
@@ -43,7 +45,9 @@ typedef struct
 
   struct {
     int n_paints;
-    uint32_t fb_id;
+    int n_presentations;
+    int n_direct_scanouts;
+    GList *fb_ids;
   } scanout;
 
   gboolean wait_for_scanout;
@@ -73,7 +77,7 @@ meta_test_kms_render_basic (void)
   gulong handler_id;
 
   test = (KmsRenderingTest) {
-    .number_of_frames_left = 10,
+    .number_of_frames_left = N_FRAMES_PER_TEST,
     .loop = g_main_loop_new (NULL, FALSE),
   };
   handler_id = g_signal_connect (stage, "after-update",
@@ -95,7 +99,6 @@ on_scanout_before_update (ClutterStage     *stage,
                           KmsRenderingTest *test)
 {
   test->scanout.n_paints = 0;
-  test->scanout.fb_id = 0;
 }
 
 static void
@@ -106,6 +109,7 @@ on_scanout_before_paint (ClutterStage     *stage,
 {
   CoglScanout *scanout;
   MetaDrmBuffer *buffer;
+  uint32_t fb_id;
 
   scanout = clutter_stage_view_peek_scanout (stage_view);
   if (!scanout)
@@ -113,8 +117,14 @@ on_scanout_before_paint (ClutterStage     *stage,
 
   g_assert_true (META_IS_DRM_BUFFER (scanout));
   buffer = META_DRM_BUFFER (scanout);
-  test->scanout.fb_id = meta_drm_buffer_get_fb_id (buffer);
-  g_assert_cmpuint (test->scanout.fb_id, >, 0);
+
+  fb_id = meta_drm_buffer_get_fb_id (buffer);
+  g_assert_cmpuint (fb_id, >, 0);
+  test->scanout.fb_ids = g_list_append (test->scanout.fb_ids,
+                                        GUINT_TO_POINTER (fb_id));
+
+  /* Triple buffering, but no higher */
+  g_assert_cmpuint (g_list_length (test->scanout.fb_ids), <=, 2);
 }
 
 static void
@@ -143,12 +153,12 @@ on_scanout_presented (ClutterStage     *stage,
   MetaDeviceFile *device_file;
   GError *error = NULL;
   drmModeCrtc *drm_crtc;
+  uint32_t first_fb_id_expected;
 
-  if (test->wait_for_scanout && test->scanout.n_paints > 0)
+  if (test->wait_for_scanout && test->scanout.fb_ids == NULL)
     return;
 
-  if (test->wait_for_scanout && test->scanout.fb_id == 0)
-    return;
+  test->scanout.n_presentations++;
 
   device_pool = meta_backend_native_get_device_pool (backend_native);
 
@@ -167,15 +177,41 @@ on_scanout_presented (ClutterStage     *stage,
   drm_crtc = drmModeGetCrtc (meta_device_file_get_fd (device_file),
                              meta_kms_crtc_get_id (kms_crtc));
   g_assert_nonnull (drm_crtc);
-  if (test->scanout.fb_id == 0)
-    g_assert_cmpuint (drm_crtc->buffer_id, !=, test->scanout.fb_id);
+
+  if (test->scanout.fb_ids)
+    {
+      test->scanout.n_direct_scanouts++;
+      first_fb_id_expected = GPOINTER_TO_UINT (test->scanout.fb_ids->data);
+      test->scanout.fb_ids = g_list_delete_link (test->scanout.fb_ids,
+                                                 test->scanout.fb_ids);
+    }
   else
-    g_assert_cmpuint (drm_crtc->buffer_id, ==, test->scanout.fb_id);
+    {
+      first_fb_id_expected = 0;
+    }
+
+  /* The buffer ID won't match on the first frame because switching from
+   * triple buffered compositing to double buffered direct scanout takes
+   * an extra frame to drain the queue. Thereafter we are in direct scanout
+   * mode and expect the buffer IDs to match.
+   */
+  if (test->scanout.n_presentations > 1)
+    {
+      if (first_fb_id_expected == 0)
+        g_assert_cmpuint (drm_crtc->buffer_id, !=, first_fb_id_expected);
+      else
+        g_assert_cmpuint (drm_crtc->buffer_id, ==, first_fb_id_expected);
+    }
+
   drmModeFreeCrtc (drm_crtc);
 
   meta_device_file_release (device_file);
 
-  g_main_loop_quit (test->loop);
+  test->number_of_frames_left--;
+  if (test->number_of_frames_left <= 0)
+    g_main_loop_quit (test->loop);
+  else
+    clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
 }
 
 typedef enum
@@ -214,7 +250,9 @@ meta_test_kms_render_client_scanout (void)
   g_assert_nonnull (wayland_test_client);
 
   test = (KmsRenderingTest) {
+    .number_of_frames_left = N_FRAMES_PER_TEST,
     .loop = g_main_loop_new (NULL, FALSE),
+    .scanout = {0},
     .wait_for_scanout = TRUE,
   };
 
@@ -240,7 +278,8 @@ meta_test_kms_render_client_scanout (void)
   clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
   g_main_loop_run (test.loop);
 
-  g_assert_cmpuint (test.scanout.fb_id, >, 0);
+  g_assert_cmpint (test.scanout.n_presentations, ==, N_FRAMES_PER_TEST);
+  g_assert_cmpint (test.scanout.n_direct_scanouts, ==, N_FRAMES_PER_TEST);
 
   g_debug ("Unmake fullscreen");
   window = meta_find_window_from_title (test_context, "dma-buf-scanout-test");
@@ -262,10 +301,15 @@ meta_test_kms_render_client_scanout (void)
   g_assert_cmpint (buffer_rect.y, ==, 10);
 
   test.wait_for_scanout = FALSE;
+  test.number_of_frames_left = N_FRAMES_PER_TEST;
+  test.scanout.n_presentations = 0;
+  test.scanout.n_direct_scanouts = 0;
+
   clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
   g_main_loop_run (test.loop);
 
-  g_assert_cmpuint (test.scanout.fb_id, ==, 0);
+  g_assert_cmpint (test.scanout.n_presentations, ==, N_FRAMES_PER_TEST);
+  g_assert_cmpint (test.scanout.n_direct_scanouts, ==, 0);
 
   g_debug ("Moving back to 0, 0");
   meta_window_move_frame (window, TRUE, 0, 0);
@@ -277,10 +321,15 @@ meta_test_kms_render_client_scanout (void)
   g_assert_cmpint (buffer_rect.y, ==, 0);
 
   test.wait_for_scanout = TRUE;
+  test.number_of_frames_left = N_FRAMES_PER_TEST;
+  test.scanout.n_presentations = 0;
+  test.scanout.n_direct_scanouts = 0;
+
   clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
   g_main_loop_run (test.loop);
 
-  g_assert_cmpuint (test.scanout.fb_id, >, 0);
+  g_assert_cmpint (test.scanout.n_presentations, ==, N_FRAMES_PER_TEST);
+  g_assert_cmpint (test.scanout.n_direct_scanouts, ==, N_FRAMES_PER_TEST);
 
   g_signal_handler_disconnect (stage, before_update_handler_id);
   g_signal_handler_disconnect (stage, before_paint_handler_id);

Places

File Support-Dynamic-triple-double-buffering.patch of Package mutter (Revision ca30a3cacfdf47d5c4e7c2293aa6615a)

Places