EXA: Improve the algorithm used for tracking offscreen pixmap use.

Replace the current score keeping algorithm with a rolling counter that's
incremented in ExaOffscreenMarkUsed, with the previous value being stored
in the area.  exaOffscreenAlloc uses the difference between the counter
value and the value in the area when deciding which area to evict.
It now also takes the size of the areas into account, and favors evicting
smaller areas.

The credit for these ideas goes to Michel Dänzer.

1 files changed, 1 insertions, 0 deletions

diff --git a/exa/exa_priv.h b/exa/exa_priv.h
index 89f47184f..e41f46aba 100644
--- a/exa/exa_priv.h
+++ b/exa/exa_priv.h
@@ -120,6 +120,7 @@ typedef struct {
     Bool			 checkDirtyCorrectness;
     unsigned			 disableFbCount;
     Bool			 optimize_migration;
+    unsigned			 offScreenCounter;
 } ExaScreenPrivRec, *ExaScreenPrivPtr;
 
 /*