yaffs Tweak gc parameters

This will reduce unnecessary garbace collection by limiting in-thread garbage
collection to when the garbage > 3/4 of the free space.

This should push more gc into background and make the write path faster.

Signed-off-by: Charles Manning <cdhmanning@gmail.com>

diff --git a/yaffs_guts.c b/yaffs_guts.c
index 389a57ca79f25efb475ef3e1311f3e6e4ab3c8b5..75eeb84cf3d5d23459d9897fa2b1fbc9e5b9c88c 100644 (file)
--- a/yaffs_guts.c
+++ b/yaffs_guts.c
@@ -2435,7 +2435,16 @@ static unsigned yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
                        threshold = dev->param.nChunksPerBlock;
                        iterations = nBlocks;
                } else {
                        threshold = dev->param.nChunksPerBlock;
                        iterations = nBlocks;
                } else {

-                       int maxThreshold = dev->param.nChunksPerBlock/2;
+                       int maxThreshold;
+
+                       if(background)
+                               maxThreshold = dev->param.nChunksPerBlock/2;
+                       else
+                               maxThreshold = dev->param.nChunksPerBlock/8;
+
+                       if(maxThreshold <  YAFFS_GC_PASSIVE_THRESHOLD)
+                               maxThreshold = YAFFS_GC_PASSIVE_THRESHOLD;
+

                        threshold = background ?
                                (dev->gcNotDone + 2) * 2 : 0;
                        if(threshold <YAFFS_GC_PASSIVE_THRESHOLD)
                        threshold = background ?
                                (dev->gcNotDone + 2) * 2 : 0;
                        if(threshold <YAFFS_GC_PASSIVE_THRESHOLD)


@@ -2537,10 +2546,8 @@ static int yaffs_CheckGarbageCollection(yaffs_Device *dev, int background)
        int aggressive = 0;
        int gcOk = YAFFS_OK;
        int maxTries = 0;
        int aggressive = 0;
        int gcOk = YAFFS_OK;
        int maxTries = 0;

-

        int minErased;
        int erasedChunks;
        int minErased;
        int erasedChunks;

-

        int checkpointBlockAdjust;
 
        if(dev->param.gcControl &&
        int checkpointBlockAdjust;
 
        if(dev->param.gcControl &&


@@ -2568,6 +2575,9 @@ static int yaffs_CheckGarbageCollection(yaffs_Device *dev, int background)
                if (dev->nErasedBlocks < minErased)
                        aggressive = 1;
                else {
                if (dev->nErasedBlocks < minErased)
                        aggressive = 1;
                else {

+                       if(!background && erasedChunks > (dev->nFreeChunks / 4))
+                               break;
+

                        if(dev->gcSkip > 20)
                                dev->gcSkip = 20;
                        if(erasedChunks < dev->nFreeChunks/2 ||
                        if(dev->gcSkip > 20)
                                dev->gcSkip = 20;
                        if(erasedChunks < dev->nFreeChunks/2 ||