Metadata page refresh

[htherrien]

After detecting a certain bit-flip threshold (e.g.: 4 bit flips for 8 bit-flip tolerant ecc scheme) when reading data, it is a good idea to remap (refresh) a page. For sectors, this can be done by manually following a dhara_map_read() operation by a dhara_map_write() to the same sector. Is there a way to handle this condition when the read page is a metadata page?

[dlbeer]

On Thu, Sep 19, 2019 at 06:04:31AM -0700, htherrien wrote: After a detecting a certain bit-flip threshold (e.g.: 4 bit flips for 8 bit-flip tolerant ecc scheme) when reading data, it is a good idea to remap (refresh) a page. For sectors, this can be done by manually following a dhara_map_read() operation by a dhara_map_write() to the same sector. Is there a way to handle this condition when the read page is a metadata page?

Nothing explicit, but every metadata and user page will eventually be rewritten as garbage collection progresses. One strategy you might use to deal with read stress is just to execute explicit garbage collection steps at regular intervals. If the rate of reads is bounded, this will place a bound on the ratio of reads to rewrites. Cheers, Daniel

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-- Daniel Beer <dlbeer@gmail.com> http://dlbeer.co.nz/ PGP: BA6E 0B26 1F89 246C E3F3 C910 1E58 C43A 160A 553B