On Mon, 2007-01-01 at 23:22 +0100, Arnd Bergmann wrote: > There are multiple efforts in progress to get a jffs2 replacement. NAND > flash in embedded devices has the same size as it has on MMC card > potentially, so we will need one soon. David Woodhouse has pushed the > limit that jffs2 can reasonably used to 512MB, which is the size used > in the OLPC XO laptop. If there are ways to get beyond that (which I > find unlikely), there will be a hard limit 2GB or 4GB because of > limitations in the fs layout.
The main weakness of JFFS2 (at this kind of size) is that there _is_ no fs layout -- so there isn't a hard 2GiB or 4GiB limit in the format, because we never encode offsets anywhere but in memory. We'll push JFFS2 further than the current 512MiB by enlarging the data nodes -- so each node covers something like 16KiB of data instead of only 4KiB, and then there'll be about 1/3 as many of them, which will cut the memory usage and reduce the amount we need to read in the "summary" blocks. But logfs is the way forward, I agree. -- dwmw2 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
