Re: UBI fastmap updates

Richard Weinberger
2012-08-03T08:57:10Z

Am Fri, 03 Aug 2012 11:47:17 +0300
schrieb Artem Bityutskiy <artem.bityutskiy@linux.intel.com>:

> On Mon, 2012-07-09 at 14:18 +0200, Richard Weinberger wrote:
> > This is the next round of UBI fastmap updates.
> > It fixes all issues pointed out by Shmulik. :-)
> >
> > If you want to test fastmap you can use my git repo:
> > git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubi2.git ubi2/v17
>
> Richard,
>
> I've added 'stress-test.sh' script to the UBI tests. This script runs
> UBI tests on nandsim of different geometry. I plan to extend it
> further: add mtdram tests, test with bit-flips emulation enabled, may
> be something else.
>
> We need to make sure all the tests pass and fastmap does not introduce
> regressions.
>
> Feel free to send patches. I am going to extend the test today, so
> 'git pull' from time to time.
>
> The tests will run very long time, so for debugging you can always
> comment out unneeded things.
>
> ATM, I have only nandsim tests with different geometry: 64MiB to 1GiB
> total size, 2KiB and 512 byte pages, 16-256KiB eraseblocks.
>
> Currently I am running this to unpatched UBI to check if they really
> pass.
>
> I tried to run it on the patched UBI and hit this issue:
>
> ======================================================================
> 16MiB nandsim with 16KiB PEB, 512KiB NAND pages, fastmap enabled
> Loaded NAND simulator (16MiB, 16KiB eraseblock, 512 bytes NAND page)
> Running mkvol_basic /dev/ubi0
> Running mkvol_bad /dev/ubi0
> Running mkvol_paral /dev/ubi0
> Running rsvol /dev/ubi0
> Running io_basic /dev/ubi0
> [io_basic] test_basic():70: function write() failed with error 28 (No
> space left on device)
> [io_basic] test_basic():70: written = 15808000, ret = -1
> Error: io_basic failed
> FAILURE
> ======================================================================
>
> On non-patched UBI it works. I think it is exactly what I was talking
> about yesterday - fastmap grows unexpectedly because you do not
> reserve the space.

Yeah, this must be the case.
I'm wondering why the test passes with the default nandsim settings?
I have also tested with other flash sizes and did lots of tests on
real hardware.

Thanks,
//richard