Re: [PATCH 4/6] persistent_ram: Move to fs/pstore/ram_core.c

From: Arve Hjønnevåg
Date: Wed May 16 2012 - 19:46:26 EST


On Wed, May 16, 2012 at 5:43 AM, Anton Vorontsov
<anton.vorontsov@xxxxxxxxxx> wrote:
> This is a first step for adding ECC support for pstore RAM backend: we
> will use the persistent_ram routines, kindly provided by Google.
>
> Basically, persistent_ram is a set of helper routines to deal with the
> [optionally] ECC-protected persistent ram regions.
>
...
> +static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
> +       size_t buffer_size)
> +{
> +       int numerr;
> +       struct persistent_ram_buffer *buffer = prz->buffer;
> +       int ecc_blocks;
> +
> +       if (!prz->ecc)
> +               return 0;
> +
> +       prz->ecc_block_size = 128;
> +       prz->ecc_size = 16;

I realize you are just moving code here, but 16 ecc bytes for per 128
bytes of data can only correct 8 bad bytes, which is not always
sufficient. At some point this will need to be made configurable
again.

--
Arve Hjønnevåg
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