block: add documentation for io_timeout

Add documentation for /sys/block/<disk>/queue/io_timeout.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Weiping Zhang 2018-12-26 11:56:33 +08:00 committed by Jens Axboe
parent 59f75fd0e3
commit bb351abaf5
2 changed files with 16 additions and 0 deletions

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@ -279,3 +279,12 @@ Description:
size in 512B sectors of the zones of the device, with
the eventual exception of the last zone of the device
which may be smaller.
What: /sys/block/<disk>/queue/io_timeout
Date: November 2018
Contact: Weiping Zhang <zhangweiping@didiglobal.com>
Description:
io_timeout is the request timeout in milliseconds. If a request
does not complete in this time then the block driver timeout
handler is invoked. That timeout handler can decide to retry
the request, to fail it or to start a device recovery strategy.

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@ -67,6 +67,13 @@ If set to a value larger than 0, the kernel will put the process issuing
IO to sleep for this amount of microseconds before entering classic
polling.
io_timeout (RW)
---------------
io_timeout is the request timeout in milliseconds. If a request does not
complete in this time then the block driver timeout handler is invoked.
That timeout handler can decide to retry the request, to fail it or to start
a device recovery strategy.
iostats (RW)
-------------
This file is used to control (on/off) the iostats accounting of the