JFFS2 SUMMARY nodes aren't working
joakim.tjernlund at transmode.se
Tue Mar 27 09:16:56 EDT 2007
On Tue, 2007-03-27 at 14:53 +0200, Ferenc Havasi wrote:
> Joakim Tjernlund írta:
> > On a fresh JFFS2 root FS image with summary nodes there is no
> > difference in mount time when enabling summary support in kernel(2.6.20,
> > powerpc).
> If you use NOR flash with relatively small erase block, summary will not
> really chance to speed up the mount process.
> Anyway you should check the summary is really working or not. Use the
> following way:
> Enable the JFFS33 debugging options (min. debug level 1) in your kernel
> configuration and recompile the kernel. You see the following messages
> in your kernel log. When you load the jffs2 kernel module you can see
> the following message:
> "JFFS2 version 2.2. NAND SUMMARY" (in case of summary is enabled, maybe
> the NAND is skipped if you doesn't have writebuffer compiled in).
> If summary is enabled and something went wrong, maybe the image on flash
> has no summary info:
> "no summary found in jeb 0x%08x. Apply original scan." where %08x is
> replaced by the offset of the jeb.
> If you see debug information which begin with "jffs2_sum_" and there is
> no error in your log it means the summary works.
Thanks, but it turned out that summary wasn't my problem. It was
excessive scanning of empty erase blocks that took time.
See my later posts and [PATCH] Speed up mount for cfi_cmdset_0001 users
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