2017-11-04 16:34:33

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH 04/15] brd: remove dax support

On 10/31/2017 05:21 PM, Dan Williams wrote:
> DAX support in brd is awkward because its backing page frames are
> distinct from the ones provided by pmem, dcssblk, or axonram. We need
> pfn_t_devmap() entries to fully support DAX, and the limited DAX support
> for pfn_t_special() page frames is not interesting for brd when pmem is
> already a superset of brd. Lastly, brd is the only dax capable driver
> that may sleep in its ->direct_access() implementation. So it causes a
> global burden with no net gain of kernel functionality.
>
> For all these reasons, remove DAX support.

Reviewed-by: Jens Axboe <[email protected]>

--
Jens Axboe


From 1582986524400661613@xxx Thu Nov 02 20:13:11 +0000 2017
X-GM-THRID: 1582818041467251394
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread