From 1163010418a7f0c60c309743498cb6c5cd828ecc Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 8 Dec 2021 16:38:30 -0800 Subject: [PATCH] docs: sysfs-block: document stable_writes /sys/block//queue/stable_writes is completely undocumented. Document it. Reviewed-by: Bart Van Assche Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20211209003833.6396-6-ebiggers@kernel.org Signed-off-by: Jens Axboe --- Documentation/ABI/stable/sysfs-block | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index de3b86a3dfa5..288626e8cb53 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -516,6 +516,23 @@ Description: scheduler module, if it isn't already present in the system. +What: /sys/block//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//queue/throttle_sample_time Date: March 2017 Contact: linux-block@vger.kernel.org