UBI memory usage on large page nand

[Nicholas]

Dear Artem,

Thanks for the advices. I'll try start for UBI first.

Reducing peb_buf would mean i need to modify the ubi IO for read/write.
As i know, ubi did an erase for a whole block before start writing,

Please correct me if i've written in a wrong way.

Alex

On Fri, Apr 15, 2011 at 9:17 PM, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
> On Fri, 2011-04-15 at 16:13 +0300, Artem Bityutskiy wrote:
>> On Fri, 2011-04-15 at 17:23 +0800, Nicholas wrote:
>> > Dear Artem,
>> >
>> > Thanks for the information. Indeed it has flexibility to be freed or consumed.
>> > Due to my case, i need to use maximum memory space while in the
>> > meantime i also need to write files into nand via ubi.
>> > 8KB page of nand flash will consume 16MB for a single volume on a
>> > single UBI MTD.
>> >
>> > 1. Is there any idea to reduce the memory consumption ?
>>
>> Yes. The main idea is as I described: both UBI and UBIFS have several
>> multiple PEB-size buffers at attach/mount time. I did not count them,
>> but I think there may be about 6 of them. All these buffers are
>> allocated using vmalloc(), so you can easily fine all of them, because
>> 'vmalloc()' is used only for those buffers.
>
> And note, this is all off the top of my head, I might be mistaken
> somewhere. If you need this - you need to spend time with the code and
> try. I'm all yours helping you by looking at your patches and advising.
>
> --
> Best Regards,
> Artem Bityutskiy (Артём Битюцкий)
>
>