On Tue, Nov 27, 2018 at 8:25 PM Damien Le Moal <damien.lemoal@xxxxxxx> wrote:
>
> Add the description of the zoned, nr_zones and chunk_sectors sysfs queue
> attributes to Documentation/block/queue-sysfs.txt. The description of
> the zoned and chunk_sector attributes are mostly copied from
> ABI/testing/sysfs-block. While at it, also fix a typo in the description
> of the io_poll_delay attribute.
>
> nr_zones description is also added to ABI/testing/sysfs-block and
> contyact email address updated for the zoned attribute.
>
> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-block | 10 ++++++++-
> Documentation/block/queue-sysfs.txt | 29 ++++++++++++++++++++++++++-
> 2 files changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
> index dea212db9df3..3789b32759dd 100644
> --- a/Documentation/ABI/testing/sysfs-block
> +++ b/Documentation/ABI/testing/sysfs-block
> @@ -244,7 +244,7 @@ Description:
>
> What: /sys/block/<disk>/queue/zoned
> Date: September 2016
> -Contact: Damien Le Moal <damien.lemoal@xxxxxxxx>
> +Contact: Damien Le Moal <damien.lemoal@xxxxxxx>
> Description:
> zoned indicates if the device is a zoned block device
> and the zone model of the device if it is indeed zoned.
> @@ -259,6 +259,14 @@ Description:
> zone commands, they will be treated as regular block
> devices and zoned will report "none".
>
> +What: /sys/block/<disk>/queue/nr_zones
> +Date: November 2018
> +Contact: Damien Le Moal <damien.lemoal@xxxxxxx>
> +Description:
> + nr_zones indicates the total number of zones of a zoned block
> + device ("host-aware" or "host-managed" zone model). For regular
> + block devices, the value is always 0.
> +
> What: /sys/block/<disk>/queue/chunk_sectors
> Date: September 2016
> Contact: Hannes Reinecke <hare@xxxxxxxx>
> diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
> index 2c1e67058fd3..a23952567008 100644
> --- a/Documentation/block/queue-sysfs.txt
> +++ b/Documentation/block/queue-sysfs.txt
> @@ -64,7 +64,7 @@ guess, the kernel will put the process issuing IO to sleep for an amount
> of time, before entering a classic poll loop. This mode might be a
> little slower than pure classic polling, but it will be more efficient.
> If set to a value larger than 0, the kernel will put the process issuing
> -IO to sleep for this amont of microseconds before entering classic
> +IO to sleep for this amount of microseconds before entering classic
> polling.
>
> iostats (RW)
> @@ -194,4 +194,31 @@ blk-throttle makes decision based on the samplings. Lower time means cgroups
> have more smooth throughput, but higher CPU overhead. This exists only when
> CONFIG_BLK_DEV_THROTTLING_LOW is enabled.
>
> +zoned (RO)
> +----------
> +This indicates if the device is a zoned block device and the zone model of the
> +device if it is indeed zoned. The possible values indicated by zoned are
> +"none" for regular block devices and "host-aware" or "host-managed" for zoned
> +block devices. The characteristics of host-aware and host-managed zoned block
> +devices are described in the ZBC (Zoned Block Commands) and ZAC
> +(Zoned Device ATA Command Set) standards. These standards also define the
> +"drive-managed" zone model. However, since drive-managed zoned block devices
> +do not support zone commands, they will be treated as regular block devices
> +and zoned will report "none".
> +
> +nr_zones (RO)
> +-------------
> +For zoned block devices (zoned attribute indicating "host-managed" or
> +"host-aware"), this indicates the total number of zones of the device.
> +This is always 0 for regular block devices.
> +
> +chunk_sectors (RO)
> +------------------
> +This has different meaning depending on the type of the block device.
> +For a RAID device (dm-raid), chunk_sectors indicates the size in 512B sectors
> +of the RAID volume stripe segment. For a zoned block device, either host-aware
> +or host-managed, chunk_sectors indicates the size of 512B sectors of the zones
> +of the device, with the eventual exception of the last zone of the device which
> +may be smaller.
> +
For the part that says, "...chunk_sectors indicates the size of 512B
sectors of the zones of the device", should it be this instead?
"...chunk_sectors indicates the size in 512B sectors of the zones of the device"
Thanks,
Bryan
> Jens Axboe <jens.axboe@xxxxxxxxxx>, February 2009
> --
> 2.19.1
>
