Add an additional meaning to the "dirty" flag. Now, if !dirty && !area, the

    pixmaps's contents are undefined, so we won't need to upload the
    undefined contents in MoveIn. Use the ExaCheck* for async ops as well,
    so that dirty is always tracked. While the performance impact for my ls
    -lR test was not significant (though the avoiding-upload path was being
    hit), it's likely to be important for the upcoming Get/PutImage
    acceleration from ajax.

5 files changed, 62 insertions, 16 deletions

diff --git a/exa/exa.c b/exa/exa.c
index 2b9dc63dd..c8e57e440 100644
--- a/exa/exa.c
+++ b/exa/exa.c
@@ -159,6 +159,10 @@ exaPixmapSave (ScreenPtr pScreen, ExaOffscreenArea *area)
     pPixmap->devPrivate.ptr = dst;
     pPixmap->drawable.serialNumber = NEXT_SERIAL_NUMBER;
     pExaPixmap->area = NULL;
+    /* Mark it dirty now, to say that there is important data in the
+     * system-memory copy.
+     */
+    pExaPixmap->dirty = TRUE;
 }
 
 static int
@@ -238,6 +242,16 @@ exaMoveInPixmap (PixmapPtr pPixmap)
 	return;
     }
 
+    /* If the "dirty" flag has never been set on the in-memory pixmap, then
+     * nothing has been written to it, so the contents are undefined and we can
+     * avoid the upload.
+     */
+    if (!pExaPixmap->dirty) {
+	DBG_MIGRATE(("saved upload of %dx%d\n", pPixmap->drawable.width,
+		     pPixmap->drawable.height));
+	return;
+    }
+
     pExaPixmap->dirty = FALSE;
 
     if (pExaScr->info->accel.UploadToScreen)
diff --git a/exa/exa_accel.c b/exa/exa_accel.c
index 2b9dc63dd..c8e57e440 100644
--- a/exa/exa_accel.c
+++ b/exa/exa_accel.c
@@ -159,6 +159,10 @@ exaPixmapSave (ScreenPtr pScreen, ExaOffscreenArea *area)
     pPixmap->devPrivate.ptr = dst;
     pPixmap->drawable.serialNumber = NEXT_SERIAL_NUMBER;
     pExaPixmap->area = NULL;
+    /* Mark it dirty now, to say that there is important data in the
+     * system-memory copy.
+     */
+    pExaPixmap->dirty = TRUE;
 }
 
 static int
@@ -238,6 +242,16 @@ exaMoveInPixmap (PixmapPtr pPixmap)
 	return;
     }
 
+    /* If the "dirty" flag has never been set on the in-memory pixmap, then
+     * nothing has been written to it, so the contents are undefined and we can
+     * avoid the upload.
+     */
+    if (!pExaPixmap->dirty) {
+	DBG_MIGRATE(("saved upload of %dx%d\n", pPixmap->drawable.width,
+		     pPixmap->drawable.height));
+	return;
+    }
+
     pExaPixmap->dirty = FALSE;
 
     if (pExaScr->info->accel.UploadToScreen)
diff --git a/exa/exa_migration.c b/exa/exa_migration.c
index 2b9dc63dd..c8e57e440 100644
--- a/exa/exa_migration.c
+++ b/exa/exa_migration.c
@@ -159,6 +159,10 @@ exaPixmapSave (ScreenPtr pScreen, ExaOffscreenArea *area)
     pPixmap->devPrivate.ptr = dst;
     pPixmap->drawable.serialNumber = NEXT_SERIAL_NUMBER;
     pExaPixmap->area = NULL;
+    /* Mark it dirty now, to say that there is important data in the
+     * system-memory copy.
+     */
+    pExaPixmap->dirty = TRUE;
 }
 
 static int
@@ -238,6 +242,16 @@ exaMoveInPixmap (PixmapPtr pPixmap)
 	return;
     }
 
+    /* If the "dirty" flag has never been set on the in-memory pixmap, then
+     * nothing has been written to it, so the contents are undefined and we can
+     * avoid the upload.
+     */
+    if (!pExaPixmap->dirty) {
+	DBG_MIGRATE(("saved upload of %dx%d\n", pPixmap->drawable.width,
+		     pPixmap->drawable.height));
+	return;
+    }
+
     pExaPixmap->dirty = FALSE;
 
     if (pExaScr->info->accel.UploadToScreen)
diff --git a/exa/exa_priv.h b/exa/exa_priv.h
index db83d1b32..c28e269ab 100644
--- a/exa/exa_priv.h
+++ b/exa/exa_priv.h
@@ -119,8 +119,12 @@ typedef struct {
     int		    devKind;
     DevUnion	    devPrivate;
 
-    /* True if the in-screen copy has been modified compared to the
-     * system-memory copy.
+    /* If area is NULL, then dirty == TRUE means that the pixmap has been
+     * modified, so the contents are defined.  Used to avoid uploads of
+     * undefined data.
+     * If area is non-NULL, then dirty == TRUE means that the in-framebuffer
+     * copy has been changed from the system-memory copy.  Used to avoid
+     * downloads of unmodified data.
      */
     Bool	    dirty;
     unsigned int    size;
diff --git a/exa/exa_unaccel.c b/exa/exa_unaccel.c
index d6e111e79..8586405a4 100644
--- a/exa/exa_unaccel.c
+++ b/exa/exa_unaccel.c
@@ -331,26 +331,26 @@ ExaCheckComposite (CARD8      op,
  * do migration for CopyArea.
  */
 const GCOps exaAsyncPixmapGCOps = {
-    fbFillSpans,
-    fbSetSpans,
-    fbPutImage,
+    ExaCheckFillSpans,
+    ExaCheckSetSpans,
+    ExaCheckPutImage,
     exaCopyArea,
     ExaCheckCopyPlane,
-    fbPolyPoint,
-    fbPolyLine,
-    fbPolySegment,
-    fbPolyRectangle,
-    fbPolyArc,
-    fbFillPolygon,
-    fbPolyFillRect,
-    fbPolyFillArc,
+    ExaCheckPolyPoint,
+    ExaCheckPolylines,
+    ExaCheckPolySegment,
+    ExaCheckPolyRectangle,
+    ExaCheckPolyArc,
+    ExaCheckFillPolygon,
+    ExaCheckPolyFillRect,
+    ExaCheckPolyFillArc,
     miPolyText8,
     miPolyText16,
     miImageText8,
     miImageText16,
-    fbImageGlyphBlt,
-    fbPolyGlyphBlt,
-    fbPushPixels
+    ExaCheckImageGlyphBlt,
+    ExaCheckPolyGlyphBlt,
+    ExaCheckPushPixels
 #ifdef NEED_LINEHELPER
     ,NULL
 #endif