[PATCH 3/3] exa/mixed: Exclude frontbuffer from deferred pixmap handling.

[Maarten Maathuis]

This is it, 10 ms a short time and even with this value large amounts
of text are still not shown fluently (the impression that some pieces
are never drawn). This is on top of the previous 3 patches.

diff --git a/exa/exa_migration_mixed.c b/exa/exa_migration_mixed.c
index 4f49905..c0c730d 100644
--- a/exa/exa_migration_mixed.c
+++ b/exa/exa_migration_mixed.c
@@ -150,12 +150,26 @@ exaDamageReport_mixed(DamagePtr pDamage,
RegionPtr pRegion, void *closure)
     if (!pExaPixmap->use_gpu_copy && exaPixmapHasGpuCopy(pPixmap)) {
 	ExaScreenPriv(pPixmap->drawable.pScreen);

-	/* Front buffer: Don't wait for the block handler to copy back the data.
-	 * This avoids annoying latency if you encounter a lot of software rendering.
+	/* Front buffer: Don't wait for the block handler to copy back the
data, unless
+	 * it has been moved back in the last 10 ms. This avoid annoying latency when
+	 * troughput is low, but keeps troughput acceptable at higher levels.
 	 */
-	if (pPixmap == pScreen->GetScreenPixmap(pScreen))
-		exaMoveInPixmap_mixed(pPixmap);
-	else {
+	if (pPixmap == pScreen->GetScreenPixmap(pScreen)) {
+		CARD32 now = GetTimeInMillis();
+		if ((now - pExaScr->last_time_front_mixed_pixmap) > 10) {
+			pExaScr->last_time_front_mixed_pixmap = now;
+			exaMoveInPixmap_mixed(pPixmap);
+
+			if (pExaScr->deferred_mixed_pixmap == pPixmap)
+				pExaScr->deferred_mixed_pixmap = NULL;
+		} else {
+			if (pExaScr->deferred_mixed_pixmap &&
+			    pExaScr->deferred_mixed_pixmap != pPixmap)
+			    exaMoveInPixmap_mixed(pExaScr->deferred_mixed_pixmap);
+
+			pExaScr->deferred_mixed_pixmap = pPixmap;
+		}
+	} else {
 		if (pExaScr->deferred_mixed_pixmap &&
 		    pExaScr->deferred_mixed_pixmap != pPixmap)
 		    exaMoveInPixmap_mixed(pExaScr->deferred_mixed_pixmap);
diff --git a/exa/exa_priv.h b/exa/exa_priv.h
index e5d90d4..cb58a02 100644
--- a/exa/exa_priv.h
+++ b/exa/exa_priv.h
@@ -185,6 +185,7 @@ typedef struct {
     CARD32			 lastDefragment;
     CARD32			 nextDefragment;
     PixmapPtr			 deferred_mixed_pixmap;
+    CARD32			 last_time_front_mixed_pixmap;

     /* Reference counting for accessed pixmaps */
     struct {