On Wed, May 25, 2022 at 06:06:07PM -0700, Keith Busch wrote: > From: Keith Busch <kbusch@xxxxxxxxxx> > > User space may want to know how to align their buffers to avoid > bouncing. Export the queue attribute. > > Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx> > Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > --- > Documentation/ABI/stable/sysfs-block | 9 +++++++++ > block/blk-sysfs.c | 7 +++++++ > 2 files changed, 16 insertions(+) > > diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block > index e8797cd09aff..08f6d00df138 100644 > --- a/Documentation/ABI/stable/sysfs-block > +++ b/Documentation/ABI/stable/sysfs-block > @@ -142,6 +142,15 @@ Description: > Default value of this file is '1'(on). > > > +What: /sys/block/<disk>/queue/dma_alignment > +Date: May 2022 > +Contact: linux-block@xxxxxxxxxxxxxxx > +Description: > + Reports the alignment that user space addresses must have to be > + used for raw block device access with O_DIRECT and other driver > + specific passthrough mechanisms. > + Please keep this file in alphabetical order. - Eric
