[U-Boot] ext4 and caching

Eric Nelson
2016-03-20T15:02:33Z

Thanks Ioan,

On 03/19/2016 08:42 AM, Ioan Nicu wrote:
> Hi Eric,
>
> On Wed, Mar 16, 2016 at 11:42:55AM -0700, EXT Eric Nelson wrote:
>> Hi all,
>>
>> I've been seeing the same sort of issues repoted by Ionut
>> and as addressed by this patch:
>> http://lists.denx.de/pipermail/u-boot/2014-January/171459.html
>>
>> That patch was added in commit fc0fc50 and reverted in commit 715b56f.
>>
>> It no longer applies cleanly, and when I tried to resurrect it,
>> I saw errors traversing directories and perhaps something went
>> wrong with my merge.
>>
>> Ionut, do you have a current version of this patch?
>>
>
> We reverted that patch because it was breaking ext4 write support. I initially
> developed the patch on top of an older u-boot which didn't have write supoort
> at all.
>
> I have tried to refactor my patch to work with both read/write, but I gave up
> when I saw that the ext4 write code relied on the old behavior of
> read_allocated_block/ext4fs_get_extent_block. I could have worked around that,
> but then the whole thing would have looked like hack, so I didn't like it ...
>
> If you are interested in a current version of this patch, I could try to
> revive it. But it has the limitation I mentioned above, so I guess you could
> use it just for some ext4 read performance measurement test.
>

I do want to get rid of the performance problem, but as I suggested
by my patch set, I think that a more general-purpose cache is a better
approach.

Regards,

Eric