Commit 11630104 authored by Eric Biggers's avatar Eric Biggers Committed by Jens Axboe
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docs: sysfs-block: document stable_writes 



/sys/block/<disk>/queue/stable_writes is completely undocumented.
Document it.

Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20211209003833.6396-6-ebiggers@kernel.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 849ab826

Documentation/ABI/stable/sysfs-block

+17 −0
Original line number Diff line number Diff line
@@ -516,6 +516,23 @@ Description: 
		scheduler module, if it isn't already present in the system.





What:		/sys/block/<disk>/queue/stable_writes

Date:		September 2020

Contact:	linux-block@vger.kernel.org

Description:

		[RW] This file will contain '1' if memory must not be modified

		while it is being used in a write request to this device.  When

		this is the case and the kernel is performing writeback of a

		page, the kernel will wait for writeback to complete before

		allowing the page to be modified again, rather than allowing

		immediate modification as is normally the case.  This

		restriction arises when the device accesses the memory multiple

		times where the same data must be seen every time -- for

		example, once to calculate a checksum and once to actually write

		the data.  If no such restriction exists, this file will contain

		'0'.  This file is writable for testing purposes.





What:		/sys/block/<disk>/queue/throttle_sample_time

Date:		March 2017

Contact:	linux-block@vger.kernel.org