diff mbox series

[RFC,v4,03/20] mm: document /sys/class/bdi/<bdi>/strict_limit knob

Message ID 20221119005215.3052436-4-shr@devkernel.io (mailing list archive)
State New
Headers show
Series mm/block: add bdi sysfs knobs | expand

Commit Message

Stefan Roesch Nov. 19, 2022, 12:51 a.m. UTC 
This documents the new /sys/class/bdi/<bdi>/strict_limit knob.

Signed-off-by: Stefan Roesch <shr@devkernel.io>
---
 Documentation/ABI/testing/sysfs-class-bdi | 11 +++++++++++
 1 file changed, 11 insertions(+)
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Patch

diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi
index 6d2a2fc189dd..68b5d4018c2f 100644
--- a/Documentation/ABI/testing/sysfs-class-bdi
+++ b/Documentation/ABI/testing/sysfs-class-bdi
@@ -55,6 +55,17 @@  Description:
 	mount that is prone to get stuck, or a FUSE mount which cannot
 	be trusted to play fair.
 
+	(read-write)
+What:		/sys/class/bdi/<bdi>/strict_limit
+Date:		October 2022
+Contact:	Stefan Roesch <shr@devkernel.io>
+Description:
+	Forces per-BDI checks for the share of given device in the write-back
+	cache even before the global background dirty limit is reached. This
+	is useful in situations where the global limit is much higher than
+	affordable for given relatively slow (or untrusted) device. Turning
+	strictlimit on has no visible effect if max_ratio is equal to 100%.
+
 	(read-write)
 What:		/sys/class/bdi/<bdi>/stable_pages_required
 Date:		January 2008