On 9/30/22 17:45, Damien Le Moal wrote:
On 10/1/22 04:38, Bart Van Assche wrote:
Since this has not been mentioned in the cover letter, I want to add
that in the near future we will need these patches for Android devices.
JEDEC is working on supporting zoned storage for UFS devices, the
storage devices used in all modern Android phones. Although it would be
possible to make the offset between zone starts a power of two by
inserting gap zones between data zones, UFS vendors asked not to do this
and hence need support for zone sizes that are not a power of two. An
advantage of not having to deal with gap zones is better filesystem
performance since filesystem extents cannot span gap zones. Having to
split filesystem extents because of gap zones reduces filesystem
performance.
As mentioned many times, my opinion is that a good implementation should
*not* have any extent span zone boundaries. So personally, I do not
consider such argument as a valid justification for the non-power-of-2
zone size support.
Hi Damien,
Although the filesystem extent issue probably can be solved in software,
the argument that UFS vendors strongly prefer not to have gap zones and
hence need support for zone sizes that are not a power of two remains.
Thanks,
Bart.
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/dm-devel
