On Tuesday 29 March 2011 07:54:46 Charles Manning wrote:
> Hello All
>
> I have just pushed the first cut of block summary code to
> http://yaffs.net/gitweb?p=yaffs2/.git;a=shortlog;h=refs/heads/block-summary
>
> The block summary feature writes all the tags in a block to the last chunk
> (or in some cases chunks) of a block.
>
> Instead of reading all the tags during a scan, the summary is read as a
> single read and we have all the tags for the block. This can significantly
> reduce the number of reads during a scan and should make scanning a lot
> faster. In tests I've been doing this reduces the number of reads by a
> factor of 40 or so.
>
> If anyone would like to experiment and provide feedback I would appreciate
> that.

I have done some more tweaking. Looks promising in the  tests I have done so 
far.

I will be also looking at using the summary during garbage collection. That 
should speed up garbage collection too.

-- Charles