Charles,
Thanks for the quick reply.
I pulled all the Q&A to the top...

> Are you using Yaffs1 mode of operation? When a file is deleted the 
> chunks are marked deleted and when all the chunks in a file are 
> deleted, the erasure will occur. This can take some time.
Apparently I am... is_yaffs2 is not set.
Should this be set?
> There is some tuning, but perhaps a better option is to get a 
> background thread going for doing the gc. This will clean the decks  
> for writes to occur unimpeded.
I didn't see anything in the docs on implementing background garbage 
collection when using CONFIG_YAFFS_DIRECT
> How full is the file system?
I've got 32Mbyte for storage, and about 6M used.
> Are you using the "soft delete" feature? This defers the actual 
> deletion, but unless you have background gc running, this will just 
> move the delays into the gc.
No, disable_soft_del is set to 1.

Anyway, it sounds like what I want to do here is enable soft-delete and 
background garbage collection (separate task).
Is there any documentation on that?

Thanks much,
Ed

> Hello Ed
>
> NOR is very slow to erase and this is what is causing the issues.
>
>
> On Tue, May 6, 2014 at 6:15 AM, Ed Sutter 
> <ed.sutter@alcatel-lucent.com <mailto:ed.sutter@alcatel-lucent.com>> 
> wrote:
>
>     Hi,
>     I have YAFFS running in standalone mode for about a year now.
>     My underlying memory is NOR, and generally speaking I see a
>     write rate of about 1Mbyte every 3 seconds.  I have not tuned
>     the underlying flash accesses so I'm sure there's room for
>     improvement there.
>
>     The problem I am having is that as I add files (and remove them)
>     I notice more and more that the 3 seconds turns into 10-15
>     seconds occasionally.  I assume yaffs is doing some garbage
>     collection; however it seems to occure a lot more often than
>     necessary.  Is garbage collection likely the culprit?  If yes,
>     is there any tuning that can be done to adjust how often that
>     is done?
>
>
> There is some tuning, but perhaps a better option is to get a 
> background thread going for doing the gc. This will clean the decks  
> for writes to occur unimpeded.
>
> How full is the file system?
>
>
>     Also, is it correct to observe that the removal of a file takes
>     essentially the same amount of time as adding a file?
>
>
> Are you using Yaffs1 mode of operation? When a file is deleted the 
> chunks are marked deleted and when all the chunks in a file are 
> deleted, the erasure will occur. This can take some time.
>
>
> Are you using the "soft delete" feature? This defers the actual 
> deletion, but unless you have background gc running, this will just 
> move the delays into the gc.
>
> Let's see what we can work out here.
>
> Regards
>
> Charles
>