Re: [PATCHv4 3/9] block: export dma_alignment attribute
From: Eric Biggers <ebiggers@kernel.org>
Date: 2022-05-26 07:31:02
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linux-fsdevel
On Wed, May 25, 2022 at 06:06:07PM -0700, Keith Busch wrote:
quoted hunk ↗ jump to hunk
From: Keith Busch <kbusch@kernel.org> User space may want to know how to align their buffers to avoid bouncing. Export the queue attribute. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Johannes Thumshirn <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> --- 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@vger.kernel.org +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