[PATCH xserver 2/7] EXA: Use round robin instead of rand() for choosing eviction position.

[Michel Dänzer]

From: Michel Dänzer <daenzer at vmware.com>

This should be just as good on average but is less expensive.

Signed-off-by: Michel Dänzer <daenzer at vmware.com>
---
 exa/exa_glyphs.c |    4 ++--
 exa/exa_priv.h   |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/exa/exa_glyphs.c b/exa/exa_glyphs.c
index 5c46ec9..28aa01f 100644
--- a/exa/exa_glyphs.c
+++ b/exa/exa_glyphs.c
@@ -219,7 +219,7 @@ exaRealizeGlyphCaches(ScreenPtr    pScreen,
 	for (j = 0; j < cache->hashSize; j++)
 	    cache->hashEntries[j] = -1;
 	
-	cache->evictionPosition = rand() % cache->size;
+	cache->evictionPosition = 0;
     }
 
     /* Each cache references the picture individually */
@@ -500,7 +500,7 @@ exaGlyphCacheBufferGlyph(ScreenPtr         pScreen,
 	    exaGlyphCacheHashInsert(cache, pGlyph, pos);
 
 	    /* And pick a new eviction position */
-	    cache->evictionPosition = rand() % cache->size;
+	    cache->evictionPosition = (pos + 1) % cache->size;
 	}
 
 	exaGlyphCacheUploadGlyph(pScreen, cache, x, y, pGlyph);
diff --git a/exa/exa_priv.h b/exa/exa_priv.h
index 70de4bd..8c5ea15 100644
--- a/exa/exa_priv.h
+++ b/exa/exa_priv.h
@@ -132,7 +132,7 @@ typedef struct {
     PicturePtr picture;   /* Where the glyphs of the cache are stored */
     int yOffset;          /* y location within the picture where the cache starts */
     int columns;          /* Number of columns the glyphs are layed out in */
-    int evictionPosition; /* Next random position to evict a glyph */
+    int evictionPosition; /* Next position to evict a glyph */
 } ExaGlyphCacheRec, *ExaGlyphCachePtr;
 
 #define EXA_NUM_GLYPH_CACHES 4
-- 
1.7.5.1