Re: discard synchronous on most SSDs?

Chris Samuel
2014-03-15T22:48:46Z

On 15/03/14 22:26, Duncan wrote:

> Either that or that feature bit simply indicates trim support, not NCQ
> trim support.

You're quite right, I outsmarted myself by noticing at the fact that the
kernel tests for ATA_LOG_NCQ_SEND_RECV_DSM_TRIM and unsets that for
drives that don't support NCQ DSM TRIM and then seeing DSM TRIM in the
SATA 3.1 spec and inferred they were the same thing.

Looking closer at the kernel code that tests for what trim to use with
ATA_LOG_NCQ_SEND_RECV_DSM_TRIM it falls back to ATA_DSM_TRIM if it can't
do the NCQ version.

Mea culpa!

--
Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC